A MANUAL OF PHOTOGEAPHIC MANIPULATION. ! I i A MANUAL OF PHOTOGRAPHIC MANIPULATION TREATING OF THE PRACTICE OF THE ART: AND ITS VARIOUS APPLICATIONS TO NATURE. LAKE PRICE. LONDON : JOHN CHURCHILL, NEW BURLINGTON STREET. MDCCCLVIII. {The Author reserves to himself the right of translating this irork.'] PRINTED BY J. E. ADLARD, BARTHOLOMEW CLOSE. PREFACE. The object of the writer of the following pages perface . has been to avoid, as much as possible, all circnm- locntory preamble ; to condense into the shortest space, and in the most simple form, the informa- tion which he has to offer to the reader. At the same time, in a process the nature of which is extreme nicety in many delicate manipulations, and in which the most exact respect for necessary precautions is indispensable to a successful result, he must claim indulgence if he dwells occasionally on what at first sight might appear trifles, but on the observance or non-observance of each of which the perfection of the resulting picture is intimately connected and depends; it being, moreover, ex- tremely difficult, in cases of failure, for the. opera- tor to decide at which particular point of the VI PREFACE, Preface, manipulation the neglect has happened which may have caused his perplexity. In contributing his quota to the general stock of knowledge on this interesting art, he may probably recapitulate facts known to those ad- vanced in its practice ; which, however, are neces- sary to be impressed on the less experienced, and without which a work like the present would be incomplete. If the results of his practice in Photography should smooth some difficulties, and facilitate the progress of the student, the intentions of the writer will be attained. London; May 1st, 1858 . CONTENTS. Page INTRODUCTION . , . . 1 Discovery and Progress of Photography . . 7 PART I. THE PRODUCING AGENTS DESCRIBED. On Light . . . . .11 The Eye and the Camera . . . . 21 Lenses . . . . .30 Diaphragms . . . . . 46 PART II. THE REQUISITE APPARATUS. The Glass Studio . . . .57 The Operating Room . . . . 63 On Cameras . . . .66 Camera Stands . . . . . 72 Swing Camera Back . . .74 CONTEHT.9, Vlll CONTENTS. Page co?fTEKTs. Head Bests . . . . .76 On the Glasses . . . . . 78 Dippers . . . . .82 Scales . . . . . 83 Developing Stand . . . .84 Pneumatic Plate Holder . . . . 85 Specific Gravity Bottle . . . ib. Glass Bath . . . . . 86 Wedge wood Trays . . . .87 Developing Glasses, &c. . . . . 88 Betort Stand . . . .89 Horn Tongs . . . . . 90 Glass Bottles • . . . ib. Still . . . . . . 92 Spirit Damp . . . .93 Printing Prames .. . . . . ib. Exciting Tray ... . .94 Eocusing Cloth, &c. . . . . 95 Test and Eiltering Papers . . .96 PAET III. MANIPUL.mONS. Preparing the Camera . . . . 97 To lay the Eilm . . . .98 Exciting the Eilm . ' . . , 101 To expose the Eilm . . . .103 Time of Exposure . . . . 104 To develope the Image . . . 107 Appearances of the Image when developed . . 112 Eixing the Image . . . .115 Varnishing the Picture . . . . 116 Defects, their Causes and Bemedies . 119 CONTENTS. IX PART lY. SUBJECTS; THEIR NATURE AND TREATMENT. Portraits. .... Page 137 CONTEKTS. Taking a Group of several Figures in tlie Studio . 150 Rustic and Picturesque Figures . 157 Instantaneous Pictures . 160 Landscapes .... . 166 Architecture .... . 173 Marine Subjects . 178 Animals .... . 180 Pathology and Chirurgery . 182 Statues, Rusts, Bassi Relievi, and Bronzes . 183 Still-Life . 187 Copying Pictures, Drawings, Prints, &c. . 189 Fac-similes of Manuscripts, early printed Books, &c. . 191 Stereoscopic Pictures . 195 Interiors of Edifices, &c. . 203 Astronomical Photography . 205 Microscopic Subjects . 206 PART V. PRINTING PROCESSES. Paper . . . . . . 210 Albumenized Paper . 211 Plain salted Paper . 211 To excite the Papers . 215 To print from the Negative . 216 Toning the Proofs . . ' . . 222 X CONTENTS. PAET VI. SOLUTIONS AND CHEMICALS. The Nitrate Bath Page . 227 Nitrate of Silver . 233 Iodide of Potassium . 234 Distilled Water . ib. Alcohol . ib. Sulphuric Ether . 235 Collodion . . 236 The Toning Bath . 238 Chloride of Gold . 242 Chloride of Silver . 243 Developing Solution . ib. Pyrogallic Acid . 244 Acetic Acid . ib. The Exciting Solution for printing . 245 Fixing Solution for the Eilm . 246 Fixing Solution (for printing) . 247 Hydrosulphite of Soda . ib. A MANUAL OF PHOTOGEAPHIC MANIPULATION. INTRODUCTION. The feelings of euriosity and astonishment with inteoduct. which the discovery of Photography and its earlier photography; productions were regarded^ have now sobered down by our intimate and daily acquaintance with its results in some one or other of the numerous directions in which its powers are ap- plied. Still the very fact that it has become a com- its popularity, mon-placCj proves its extreme popularity; and the most indifferent of the pictures of its followers is not without its value in the diffusion of know- ledge^ the creation of a feeling for Art^ and an increased appreciation of the infinite wonders and beauties of Nature,, in individuals who^ without the facilities which it has given,, would probably have remained ments. entirely strangers to such enjoy- and advan- tages. 1 2 INTRODUCTION. Inteoduct. Its applica- tions to Natural History, Geography, Astronomy, Electricity, and the Mi- croscope, Antiquities, Architecture In a multiplicity of ways_, Photograpliy has already added^ and will increasingly tend to con- tribute, to the knowledge and happiness of man- kind : by its means the aspect of our globe, from the tropics to the poles, — its inhabitants, from the dusky Nubian to the pale Esquimaux, its pro- ductions, animal and vegetable, the aspect of its cities, the outline of its mountains, will be made familiar to us. The traces of those generations long ages ago passed from its surface, who, with the inherent feeling of our kind, have striven to leave to a dim posterity, by their gigantic but decaying efforts, some relic and memento of their passage; all have been or will be brought in intense reality to our very hearths. Nay, passing even beyond in its career, already have the appearances of the firmament, the minutiae of the planets, and of our satellite, been noted with unerring accuracy; the mysterious currents of electricity, and the movements of our atmosphere, are by its means exactly registered ; the marvels disclosed by the microscope are fault- lessly delineated, and in these, as in all direc- tions, we cannot put limits to its scope and powers. The antiquary and architect are indebted to it for such faithful images of the objects of their pursuit and study as they have never previously INTRODUCTION. seen^“tlie meclianist and the engineer may take intboduct. their compasses and measure the parts of each Engineering, viaduct^ engine^ or bastion^ which nature’s draw- ing has laid down to scale for them. The artist and the dilettante have seen and will see tran- scripts of the distant and scattered masterpieces of ^nd the Tine Raffaelle and Titian_, of Velazquez and Murillo^ brought together and united for near comparison in their folios; not as mere diluted translations by the hands of others^ but with their own touch, feeling, and power. The emigrant and traveller, far from their The Emi- grant and early home, send mementos from distant climes, Traveller, of halts under sultry skies, in which, surrounded by strange, swarthy figures, and shaded by the luxuriant vegetation of the tropics, the elephant and camel browsing beside them; those dear to them in distant England see the familiar face from which they may long be separated. Amidst the icy barriers which have been placed to guard the hidden mysteries of the Poles, those who have had the daring to endeavour to penetrate their awful solitudes have made use of Photography to bring away the impress of them. From Australian cabin, from Canadian log-hut. Familiar uses. come images of faces born on that distant soil, akin in blood, yet strangers to those at home who bear their name, — even the humble artisan and lowly cottar, heretofore deprived from indulgence Introduct. Historical uses. Its public im- portance in fixing pass- ing events. Summary. Anticipstiou for its fi lure. 4 INTRODUCTION. in sucli natural feelings^ may see tlie mementos of those who are, or have been, dear to them, upon the walls of their modest dwellings. Posterity, by the agency of Photography, will view the faithful image of our times; the future student, in turning the page of history, may at the same time look on the very skin, into the very eyes, of those, long since mouldered to dust, whose lives and deeds he traces in the text. As this art progresses to perfection, each im- pressive public ceremonial will he registered and delineated; nay, even the very turmoil of the battle or siege and their varying aspects will he instantly fixed and transferred, with the actors, to the page of history, by an art to which the deli- neation of thousands of figures or of a blank paper present equal facilities of execution. The foregoing are some of the benefits which Photography will confer on art, on science, and mankind, when arrived at its more mature de- velopment; and when we reflect how much has been done in the few years which have elapsed since its discovery, we need not despair of further surprising advances ; for we must not at all con- sider that it has attained the limits of its perfec- tion. Much yet remains to be done by all in- terested in its advancement, and it is to be hoped that their efibrts will, in their several departinents, be successful. INTRODUCTION. 5 To tlie natural philosoplier we must turn for introduct. new discoveries in those mysterious combinations of Light, Heat, and Electricity, wbicb may advance our knowledge of their united action, and possibly will result in giving us not only form, but colour, in the picture. To the mathematician and from the op. ^ tician, optician we look for lenses, in the performance of which the operator may not feel himself fettered and his picture limited in size ; or if he increase its dimensions, that want of intensity, weakness of definition, distortion in the proportions of the figure, and shallowness of focal depth, may not result — qualities in which, at present, more per- fection is greatly needed, and which advances, if successfully accomplished, will raise the character (improve- ments neces- of the instrument, and enable it to fulfil completely sary in por- trait-lenses,) and satisfactorily the uses for which it is in- tended. To the chemist for those improvements chemist, or new combinations in the materials used in the process, which shall considerably abbreviate the time necessary for the production of the image. And, finally, to the artist, for that judicious selec- and the tion and arrangement, whatever his materials may be — for everything in nature, even to the smallest weed, has beauties and capabilities — that the pic- tures we shall see may show marks of refiection and intelligence, and conformity to those rules of art, in the composition of their lines, and effect of their light and shade, which will cause them to be INTRODUCTION. Inteoduct. looked upon witk the respect and interest tLe ex- quisite beauty of Nature^ s own drawing should inspire,, when not marred by tbe unskilful transla- tion or promiscuous selection of her votaries. I THE DISCOVEEY AND PEOaRESS OF PHOTOGRAPHY. Without entering at much detail into the History. history of the discovery of the power possessed by light to fix^ under certain chemical conditions^, the image of objects in nature upon a plane surface, a work upon photography would be ob- viously incomplete were the rise and progress of the art passed over in silence. Photography, as its name implies, is the art of Origin of its drawing by light, which indeed is not, strictly speaking, correct, since the most illuminating portion of the sunbeam is precisely that of least photographic action. Twenty years have not elapsed since, in artistic and scientific circles, the greatest interest was excited by rumours of the fact, that Daguerre the Discovery by Daguerre. artist — well known to our public by his dioramic pictures — had succeeded in what had often been desired, and as often been pronounced hopeless, namely, in giving permanence to the pictm’e pro- 8 DISCOVERY AND PROGRESS History, duccd in tlic camcra-obscura/^ The earliest Its first re- results shown in London, in 1839, were mar- sults. vellous representations of public monuments in Paris_, views on the Seine^ kc., depicted with a minutia and accuracy which astonished the be- holder; they were on metal plaques^ and were executed by the process since called, after its inventor. Daguerreotype. But though wonderful Their nature, in the dclicacy of their finish, the reflexion from the metal plate was found objectionable, nor did they possess any power of reproduction. Fox Talbot’s Simultaneously with the discoverv bv Neipce and Daguerre in France, our own countryman, Mr. Fox Talbot, had perfected researches upon which he had been engaged in the same direction, and the result was, in 1839, made known under the name of the Talbotype or Calotype, which differed from Daguerre’s, inasmuch as it was on paper, and the picture being negative, that is, with the lights and shadows reversed, it possessed Calotype. powcr of a plate or cliche, from which an unlimited number of proofs might be printed, the diaphanous texture of the paper used allowing the passage of sufficient light. But this process had likewise its disadvantages, although they were in another direction : it was too slow in receiving the action of light, to be advantageously applied to portraiture and the Its qualities, fife, and was deficient in finesse and delicacy of OF PHOTOGRAPHY. 9 execution when landscape^ arcliitecture^ and still- history . life were treated by it. Matters stood thus when Mr. Scott Archer^ in 1851j communicated to the public a new method of taking the photographic picture by means of a thin film of collodion, extended on the surface of coUodiou process dis- a glass plate^ and rendered sensitiv^e to light by covered, being treated with salts of silver. It was found in practice to combine the excellences of all previous methods^ and possessed, besides, some peculiarly its own. It had more rapidity of action than even Daguerre^s process j it could be manipulated at infinitely larger sizes, and had an unlimited power of reproduction, of which his was incapable ; and it surpassed Mr. Talbotts by its incomparably Capabilities greater sensitiveness, its superior discrimination of textures, and minuteness of detail. This is the Collodion process, which is practised far and wide, from which unfortunately the in- ventor, instead of reaping any benefit — -as had been the case with Daguerre, to whom and his coadjutor Trance had granted pensions of 10,000 francs for life, with reversion to their families, — became impoverished by the expenses conse- quent upon his experiments in the art, and died The inventor 1 caving his widow and family to the sympathies of the public. The Collodion process may be said to have superseded all others. Its qualities have, in 10 DISCOVERY AND PROGRESS OF PHOTOGRAPHY. History. Popularity of the process. Other me- thods less satisfac- tory. Attention to minutiae necessary. practice^ been found available for every coneeiv- able subject_, and of seven hundred works in the Pbotographie Exhibition of London, of this year, 1858, six hundred are due to Collodion ; amongst them, showing its sensitiveness, pictures taken in the Txofh of ^ second. Such are the main phases of discovery and improvement in this wonderful art, from the first successful results, in 1839, to the present time ; for, although many ingenious theorems have, during the interval, been propounded, they have either been found abortive in practice or, their qualities in various ways being inferior to the others, have been allowed to fall into desue- tude. It would, therefore, serve no purpose to detain the reader by the bare enumeration of them ; the intent of this volume being to describe, with considerable minuteness, the processes of the one found to give results of the greatest excel- lence, and by that necessary prolixity, to spare the student many disappointments, and enable him, by strictly following fixed details, to produce with much certainty a successful photographic picture. PAET I. THE PRODUCING AGENTS DESCRIBED. ON LIGHT. Before proceeding to describe the manipulatory light. processes_, it will be proper to consider tbe nature its Natme. and action of tbe chief producing agent — Light — and to observe those qualities in its composition and influence which more immediately regard the formation of the photographic image. Light is that principle which emanates from all Sources of self-luminous bodies_, such as the sun_, the stars^ from electrical sources^ incandescent earths or metals,, and the flames or sparks given out from the combustion of solid bodies or gases ; and it is reflected,, with more or less intensity, from every objeet in nature, according as the structure and surface of each may be more or less fitted by the arrangement of its components, to reflect, disturb, or absorb its action. ]2 PRODUCING AGENTS. Li ght. Thcpc are several distinet qualities in liglit_, each Its qualities of which enter in some shape or other into the euuiuerated. . r> i i i • • mi production of the photographic picture. They are intensity^ reflexion (regular and irregular), refraction^ dispersion_, and absorption. Intensity due Intensity is the quality which may either arise to the source, '' ± ^ . from the power of the source_, as the sun compared with a taper_, or the greater or less density^ in quality or quantity_, of the medium it has to tra- verse to arrive at a given point; thus the sub- marine diver receives a diminished light in pro- portion to the increase of his descent^ and in the profound depths of the ocean darkness alone exists^ since even the light of the sun is powerless to traverse the accumulated waters. On the Con- or the me- trary, on the summits of lofty mountains the diumtra- ^ ^ versed. rarificd atmosphere permits us to see the stars in novel and surpassing brilliancy,, compared to our usual view of them,, and to discern many whose light was too feeble to reach our vision, through the lower strata of the earth^s atmosphere. Reflexion, Heflexion is regular^^ when the beam of ivhite natuti\’ or sunlight falls upon polished surfaces of metal, or mirrors, and is transmitted from them in its integrity ; that is to say, as white light, irregular, its It is irregular when it falls upon bodies and results ; surfaces so constructed that they take up certain portions only of the coloured rays composing white light, and reflecting those tints alone, and LIGHT. 13 absorhing the rest^ the objects themselves become i^ight. to our senses coloured, not hv any pigment they intrinsically possess_, but by the varying shades of gives cohnr to objects; power of affinity and appropriation, which their molecules have for reflecting individual rays, which are the components of light. The foregoing may be familiarly illustrated jts action ii- thus — we look at a crowded thoroughfare, we see in their varied and appropriate hues, granite, cloth, velvet, bricks, tiles, &c. ; every object has its local colour ^’ — this is due to irregular reflex- ion : a smart shower comes on, the result is that on terrestrial bodies, all those surfaces become wet, they then reflect regularly, so that in the camera, as to the artistic eye, pavement, tiles, cloth, &c. , all lose colour, and are expressed by white light. Irregular reflexion of light is the prime motor and on the atmosphere. of all that is beautiful as colour to our senses, the aqueous globules of the mid-day silvery cloud are its varying mirrors, which anon it tinges with the colours of the spectrum in the rainbow ; the rosy hues of dawn and gorgeous tints of sunset are the results of its diversified action; the endless varieties of colours, seen throughout nature, are due to its mysterious influences, reflected from myriads of facets ; as has been said, of themselves they have no colour ; palpable to touch some may be, hideous and livid they would by certain com- binations of light appear; by the glorious sun^s ray 14 PRODUCING AGENTS. Light. Refraction ; its optical qualities. Chromatics. Dispersion. Fig. 1. [A they glow resplendent in magic hues of varied beauty. Eefraction is the quality which a beam of light possesses in passing from a medium of one density_, as air^ to another as water^ glass_, &c. When it strikes upon such media^ at a right angle as a a^ it passes straight through them^ without changing its direction; when it im- pinges upon them in an oblique direction as B c, the ray is bent in its passage,, and the angle of its deviation is governed by the na- ture and density of the medium into which it enters. Advantage is taken by the optician of this quality of light, he uses in his lenses glass of different degrees of density, the nature of one sort being to disperse the beam of white light; the result is, that the coloured fringes of the spectrum surround each object, one of another quality is superposed, and the various rays are reunited and white light or achromatism results. Dispersion is the separation of a beam of white light into its component rays, which vary from each other in colour and in refrangibility. When such a beam falls obliquely upon the surface of a LIGHT. 15 prism^ it is not refracted from it in the same state^ light. but undergoes a division which enables us to sub- mit its various parts to analysis. If a hole be made in a shutter a beam of sun- The means of T 1 • • 1 • -n 1 • T separating lights in passing through it^ will be received on a piece of -white paper as a round white spot ; but if a prism be interposed in the ray_, the result will be that the image on the paper will be altered from a white circle to an elongated figure^ composed of a series of tints_, symmetrically arranged_, and which are always_, when proceeding from the same source,, identical in their disposition and colour,, each possessing qualities which differ widely in their nature; this is the decomposition of light,, and the result is called the Solar Spectrum : its divided Soiar Spec- trum. parts can be recombined in a variety of ways,, all having for their purpose the uniting of the co- loured rays. This may be effected by receiving them on a double convex lens,, in its focus a white spot will appear — which is indeed a minute image of the sun — each coloured ray may be separately How recom- bined. reflected from one of seven plain mirrors, so ad- justed that they may be converged to one point, when white light will be the result ; by rotation and several other methods. When the spectrum is formed from other spectra from other sources sources of light than the sun various changes are observed in its appearance, by the omission of some of its tints, or by change in the locality of 16 PRODUCING AGENTS. Light. BrcM^ster’s tlieory. Newton’s tlieory. The spec- trum, others ; but in the main the various spectra offer salient points of resemblance_, and most of them are capable of impressing a Photographic image of greater or less intensity. Sir David Brewster considers that white light is composed of the three primary colours^ blne^ red^ Fig. 2. MAXIMUM OF ACTINISM. LIGHT. HEAT. SOLAR SPECTRUM. A. Extra rays of heating power beyond the red. B. Invisible rays of photogenic action beyond the violet. and yellow ; and that the seven colours described by Sir Isaac Newton are formed by the overlap- ping of the edges of the rays of the three^ each having its maximum intensity at the parts where the strongest and brightest tint of that colour exists in the compound spectrum ; that is to say^ red and yellow forming orange^ blue and yellow green^ &c. ; be that as it may^ this much is cer- LIGHT. 17 lain^ that three distinct qualities — namely^ Light^ ltght. HeaTj and Actinism — are definitely referable to distinct portions of the spectrum : illuminating power or light to the yellow, heat to the red, and, according to Dr. Herschel, to the invisible qualities of Its compo- rays beyond the red; and electrical affinity and »ents ; the quality termed actinism, which is the main producer of the photographic or chemical action, to the blue and to certain rays beyond that end of the spectrum, which were discovered by Pro- fessor Stokes, and which are invisible to the unaided vision. The illuminating quality of the yellow ray is «^eans of de- judged by the eye. The second — heat — was proved to reside in the red by experiments made with delicately constructed thermometers, by Dr. Herschel and Sir Humphrey Davy, who found that at a point an inch and a half below the ex- treme red the invisible rays exercised a heating power, even when the thermometer was placed at Heat, a distance of fifty-two inches from the prism. Sir Henry Englefield gives the following scale, resulting from his experiments : Blue . Green Yellow Temperature. . . 56 °. . . 58°. . . 62°. Temperature. Bed . . . 72°. Beyond red . 79°. ^ On returning the thermometer from beyond the red into the red ray, it again fell to 72°. 2 18 PRODUCING AGENTS. ligh^ The quality existing in the hlue^ violet^ and Actinism, extva violet portions of the spectrum_, is that of the greatest importance to the Photographer ; as it is chiefly by those rays that the action is im- pressed which forms his picture. Extra rays (invisible) of Actinism. Lavender Violet . . Indigo . Blue . . Green . Yellow . Orange . Bed . . . Crimson Fig. 3. Visible Spectrum of Spectrum. photographic action ^ The early researches of Scheele in 1801, of M. Rittner of Jena, of Dr. Herschel, and Dr. Wollaston, all resulted in referring fhe power of de- Decomposes composing salts of silver, now termed actinism salts of silver. , i , to the beiore-named rays, and subsequent investi- gations have confirmed the fact. LIGHT. 19 The accompanying diagram will show the nature ltght. of the action on the position of the various parts of the spectrum in the photographic picture. It Action of the i o X X spectrum on will be observed that the part opposite the lightest ray — the yellow — remains unaffected, whilst the gradations of tone up to pure white in the blue and violet give the comparative increase between the two extremes. We thus perceive the reason that the photo- graphic action is often deficient when apparently the light is sufficiently intense, since the foregoing illuminating analysis proves that the visual ray is not the one actinic, to which we are indebted for the picture ; on the contrary, sensitive surfaces may be exposed for any periods in that ray unaffected, provided means are taken to protect them from the diffused light which scatters from the prism, or from the action of the other rays. We will do no more than notice that various experiments have been made at different times which refer a distinct and powerful magnetic The violet rays mag- action to the violet rays, many successful results have been obtained in polarizing needles and adding to the power of magnets; but on this point there is considerable controversy, and the question has yet to receive elucidation in common with much that is entirely obscure in the occult principles of light, heat, and electricity. The last quality of light, or rather condition to Absorption. 20 PRODUCING AGENTS. Light, whicli it submits^ is absorption ; this term is used Nature of when the illuminating principle is too feeble, the absorption. . ^ . . distance it has to traverse through different media is too great^ or^ the nature of the bodies on which it impinges not being favorable^ by their structure, either to its reflection or refraction, it becomes absorbed and stifled. When an attenuated beam of light is admitted into a darkened room, it will illumine an object close to the aperture where it enters ; retire the object further and further, and its obscurity in- creases, until a limit may be soon reached, in a Illustrated, large apartment, where its illuminating power ceases entirely ; this is caused by the absorption of light. Another kind of absorption is caused by the structure of surfaces, which being, like velvet, bricks, cloth, &c., porous, and offering few or no re- flecting portions, the particles of light enter their numerous minute recesses and are extinguished. It will be well that the student should note the whole of these qualities of light, since they enter intimately into the practice of Photography, either in the management of the lens and diaphragm, or study of ligiit in the selection and arrangement of the picture, necessary. governing, as they do entirely, the whole process; conformity to their nature will be the only method of arriving at successful results. 21 THE EYE AND THE CAMERA. Our means in Photograpliy of forming an imita- thk eye. tion of the image wliicli is presented to the mind by that most wonderful and perfect organ the eye, its action j ^ imitated by are the lens and the camera ; and as the picture camera, which we produce is judged entirely by its con- formity with the appearances produced by the same objects in the human eye, it will be well to examine the structure of that organ, and compare the manner in which it performs its functions with the conditions imposed on us by the camera, * so that we may see the points in which consist our greatest disadvantages ; in order to do what is possible to assimilate their action, or at all events not to increase, by injudicious treatment JSuits.^ of our instruments, the distance, already too great, which separates the two. The human eye is of a spherical form, and about an inch in diameter ; the small circular disc in front, called the cornea (a), being pro- minent beyond the other portion. Within the Comea. cornea is a small chamber (b) filled with a trans- parent liquid called the aqueous humour , which may be considered the front lens, and on which the rays proceeding from external objects first impinge. The posterior surface of the aqueous 22 PRODUCING AGENTS. liumonr is limited by tbe irisj, wbicli is in fact a Iris. diaphragm_, by tbe instant dilation or contraction Fig. 4, of wbicb tbe aperture in its centre (c) called tbe Pupil. pupil is_, according to tbe intensity of tbe light, expanded or diminisbed. Its diameter varies, from little more than a sixteenth of an inch in intense light, to above one quarter in comparative ob- scurity. This movement, wbicb may be observed by approaching or retiring a candle near tbe eye, regulates tbe proper quantity of light on tbe retina. On looking from distant objects to those im- mediately near, a contraction of size of aperture takes place in tbe pupil, and vice versa, the inten- reguiatirg tioii of wliicb movement is to admit more light tlie amount ^ retina for the distant objects, and to diminish it and suppress tbe obliquity of tbe lateral rays in near ones. THE EYE AND THE CAMERA. 23 Immediately behind the iris there is a cap- the iae . snle_, in the form of a double-convex lens (n), which is called the crystalline humour or lens, crystalline mi '1 • • 1 r* • humour; Ihis plays a most important part in the functions of the organ ; by means of the alterations which take place in it^ probably by the changes in its form and relative distance between the iris and the retina, the process of focusing objects at different distances is performed. Much discussion power of has taken place on this point, but the experiments focus of Dr. Young on persons deprived of this lens, and who were thereby incapacitated from focusing their sight, seems to put tjie question of the power possessed by this portion of the eye beyond doubt. A familiar exemplification of the act of focusing the sight, is given by placing one object at a yard distance from the ej^e, and another at six beyond exemplified, it j on looking intently at either we are conscious of the presence of the other, but we do not dis- criminate its details ; on fixing one we lose the definition of the other. The next chamber (e) is filled with the aqueous Aqueous hu- mour. humour y through which the rays pass until they, in the most true and perfect conditions of focus, impinge upon the curved surface of the retina (f), depicting the image upon it. This may be seen by carefully dissecting the hinder part of the eyeball of an ox recently killed, so as to lay bare Retina. 24 PRODUCING AGENTS. The Eye. Retina sliown to be the recipient of tbe image ; its diminu- tive size ; difficulties ol imitating its action. Its qualities recapitula- ted, the retina ; if it be now placed in an orifice in a shutter^ corresponding to it in size^ an observer in a dark room will see the images of objects without depicted upon it in an inverted position^ remarking only that as the power of adapting the focus of the eye to the planes of distances which existed in the animal alive^ may or may not be more or less defective in the unconscious organ, according as the objects presented to it may by their proxi- mity be in harmony with the conditions it happens to possess. The size of that portion of the retina which receives the image *is, in the human eye, not so large as a sixpence, and when we consider the marvellous power of sensitiveness to infinitesimal gradations of tone, and the more than micro- scopical delineation of form which it possesses, together with the perfect adaptation of aperture and perfection of focus, we become sensible of the difficulties with which the effort is sur- rounded, to produce by optical science an imita- tion in the camera of the same appearances presented to the mind through the eye. To recapitulate. W e find in the eye the following qualities — an aperture of such limited area, that for ail practical purposes it may be considered a point — power of increasing or diminishing the quantity of light admitted to the retina, and, in proportion as the objects inspected are more or less distant. THE. EYE AND THE CAMERA. 25 admitting the parallel^ or suppressing those oblique the etk. peneils which would interfere with the absolute perfection of the image — of arranging the lenses in such a manner as shall give correct focus to objects at varying distances — the whole of the above being altered simultaneously^ instanta- neously_, and in those nice gradations of proportion which the harmonious balance of the different qualities requires. Lastly^ that the delineating rays arrive at the curved surface of the retina in the precise ratio of their lengths. In the camera the lenses take the place of the The camera our means of ■P,- imitation. aqueous humour and crystalline lens ; by a strange perversity the diaphragm^ which^ performing the Diaphragm •1 1 1 T 1 ^ long incor- function of the iris and pupil, should have been rectiy ap- ^ ^ plied. placed between the pairs of lenses, has been applied in front of them, and in some instances 26 PRODUCING AGENTS. ' tjie_^. continues to be so^ to tlie manifest injury of the pieture. Tlie rays refracted from the lenses are received Ground glass on the fi'round aiass, which is the retina of the screen j cj o ^ camera. We will now consider what are the qualities possessed by the picture given by the camera^ and in what it most essentially differs from that which must be the object of our imitation — nature, as seen by the human eye. difficulties of In delineating on a plane surface, by means of ils^te«esur- ox ^ face. lenses, the appearance of objects, we labour under many disadvantages, whieh rapidly multiply as we increase the size of the pieture. This does not apply so much to representations of distant and inanimate forms, since with them the parallelism of the rays is greater, their reflecting surfaces are still life. incomparably larger, they may be taken under any condition of light up to the direct sun ray, and as they are immoveable, the diminution of aperture and consequent time of exposure is of no im- portance ; so that we may pass from the consider- ation of that class of subjects to those in whieh the difficulties to be surmounted are greater — LMng sub- namely, in the treatment of near and living objects by the double combination lens. In proportion as we approach the person to be depicted, what is called distortion in the image increases ; that is to the camera; say, tlic focal depth in the subject diminishes. THE EYE AND THE CAMERA. 27 consequently all projecting portions become en- larged^ and as the obliquity of the lateral rays be- comes greater the nearer we advance_, in order to maintain satisfactory quality in the picture_, it is ne- cessary to do precisely what is done in the human eye in such circumstances_, namely, to diminish the aperture in proportion to our advance, by chang- ing the diaphragm for one smaller in diameter. But in the camera we labour under two dis- advantages in all this — namely, that in pro- its disadvan- portion as we approach the subject the focal length between the lens and the ground glass is rapidly increasing, and as we diminish aperture we subtract light, both which add materially to the time necessary to impress an action on the film; besides these disadvantages, there is that compared imposed on us by the requirements oi the art — namely, the necessity we are under of receiving the rays forming the image on a plane surface, the consequence of which is that those rays which, if received on a curved line corresponding to their Action of ra vs • 1 . « 1 on M curved lengrth as in the retina ot the eye, would have and «ai sm-- ° ^ face. been as perfect in their form as the more central ones, become distorted by the manner in which their terminations are wudened and obliqued by the mode of their impingement, as shown at c c fig. 6; and, moreover, as their focal length was at B, D, B, it would manifestly be damaging to the picture to retain their confusing influences : 28 PRODUCING AGENTS. thts Eye , in sucli casc we must therefore submit to one of two things^ an inferior quality of picture or Lateral rays au increased time of exposure. In the camera defective. . i i i i great rapidity of action can only he obtained by Fig. 6. Apertures in large apcrturcs or short focal lengths : in the eve the camera; i i and in the wc scc that the pupil is a mere point,, yet even the eye ; instantaneous action of the electric spark perfectly suffices to depict objects on the retina. If in the camera large apertures are used the picture will be THE EYE AND THE CAMERA. 29 most incorrect^ and entirely nnlike the same oh- The eye. iect as seen by the eye, a simple proof of which is effect of theii’ j j ^ X s: diversity the following : Take a lens six inches in diameter^ and covering all its surface except an inch on one of its sides, take a picture with that portion of it ; now re- Fig. 7. Fig. 8. yersing the operation, take another with one inch ana errors • 1 . of larger ot the opposite margin ; print the two on thin apertures paper, oil them, and superpose the prints ; no two lines in them will correspond; they have been taken from two points of sight distant four inches from each other; and yet, although these two pictures are so wanting in uniformity of lines, a portrait taken with such a lens at full aperture would be much more defective, since not only two portions of its margin, but the whole of its sur- face, would have been looking round not at every , , " •'on portrai- feature and eyery form in the subject — in fact, it would not he a picture of a lion, hut a representa- tion of his extended hide. It thus appears that when the representations of near living objects are executed, moderate sizes must alone he attempted, Moderate which may he increased in proportion as the ?SSmendeT” camera is retired from the subject, and as the 30 PRODUCING AGENTS. The Eye. Optical diffi- culties. Necessity of appreciating tiie tvro con- ditions. Leivses. applicat ion by the photo- grapher ; their impor- tance in the process j reflexive area of it is augmented. Tlie use of medium sizes of lenses^ whicli will in their aetion permit a balance of disadvantageous qualities^ is desirable^ until tbe time arrives^ if ever it should^ when the apparently irreconcilable conditions are united in the lens_, which will enable the operator, with a small aperture, to cover a fair extent of surface, and to produce an image perfect in draw- ing ivith rapidity. In the meantime the photo- grapher, who aims at a successful result in this class of subjects, will do well to bestow all his attention in endeavouring to assimilate, as much as possible, the action of the camera to that of the eye, as it is by the unerring and practised com- parison of the latter his pictures will be judged. LENSES. Although the construction of lenses is the more immediate concern of the optician, the skilful application of them to their diflPerent uses is en- tirely the province of the photographer ; and his pictures will be dependent, for many of their qualities, upon his perfect knowledge or otherwise of the extent of the capabilities and nature of action of his lens. The lens is the object of primary importance in his apparatus ; it is at once an atmosphere, with LENSES. 31 novel coiiditions_, througii wMcli lie invisages na- lenses. tiire ; and the rays refracted from it are the pencils with which he delineates his picture. If it he defective in its qualities^ no matter what dexterity^ the result if neatness of manipulation^ or artistic knowledge he possess_, it will he utterly impossible for him to produce a perfect photograph. Yet even the lenses made hy the most skilful opticians leave much to he desired : the smaller diameters^ it is t^eir capa- true_, are sufficiently deep in focus^ rapid in action_, and vigorous in intensity on the glass^ and defi- nition in the picture ; hut the negatives they are capable of producing are very limited in size^ and defects, in proportion as the operator increases the dimen- sions of his picture^ and is consequently Obliged to use larger and larger lenses^ his difficulties^ in this direction alone^ multiply in an enormously increased ratio,, until the time necessary to pro- duce a picture is so prolonged as to put a veto upon subjects from the life being undertaken at all. The qualities of a lens are governed by two leading principles,, — the nature of the refraction and nature; possessed by the media composing it^ and the forms which are given to their surfaces. Lenses are generally made of glass,, but can be composed of any transparent non-cry stallized medium, pro- vided that one or both the bounding surfaces are more or less curved. 32 PRODUCING AGENTS. Lenses. their action on parallel rays j in the Science of optics. Lenses may be divided into two classes^ — tbe converging and diverging, according as the nature of the action of their curves upon parallel rays of light is to gather them to a pointy termed the focus, as the double convex_, Fig. 9. or to scatter them^ as the double concave. Fig. 10. The action of a lens may be seen drawn in the air by itself^ in the following manner : Paste on the lens a dark paper^ pierced with holes, sym- metrically arranged ; make an orifice in a shutter facing the sun, place the lens in it ; the nature of its action on parallel rays will at once become visible. Advantage is taken by the optician in the scientific adaptation of varying degrees of curved surfaces, to antagonise the distortion in the form of the image, which, were such combinations not LENSES. 33 made, would appear; tlie result of these being, lenses. when skilfully effected, to reduce the spherical aberration^'* to a miminum. There are several forms of lenses, each of which Dioptrics, gives a different quality of direction to the inci- dent ray. They are — ■ Fig. 11. 1 2 3 4 5 6 1. Double convex. 4. Double concave. 2. Plano-convex. 5. Plano-concave. 3. Concavo-convex. G. Meniscus. It has been shown, in the section on the Eye, that one of the greatest disadvantages we labour under in our imitation of its action, is the neces- Eye and lens, . . , f, . . , . difference in sity imposed on us ot receiving the image on a action. plane surface, whereas the retina is curved. The efforts of the first mathematicians have been di- rected to the study of the best arrangement of surfaces which the lenses should possess to neu- tralize this damaging condition ; and their calcu- lations, and the skill of the leading opticians of Europe, have, to a certain extent, been successful. Still, however well a lens may have been cor- rected for spherical aberration,^^ it is always a Spherical quality which, in proportion as we use the 3 34 PRODUCING AGENTS. Lenses. how in- creased ; how dimi- nished. Refraction light. whole of the diameter of the lens or advance nearer the sitter or the object delineated^ makes itself more and more felt_, and requires all the tact Fig. 12.* and skill of the operator to remedy as much as possible ; the means of doing so being by judicious adaptation of diameter of aperture to the con- ditions above named^ and will be treated of under the head of Diaphragms. When light strikes in an oblique direction on a transparent medium_, the beam is diverged from the direction it was pursuing more or less accord- ing to the refractive power it encounters in its * The dimensions of this work would not allow the diagram to be drawn on a larger scale. In order, therefore, better to mark the differences caused in the lines of the pictures, the relative size of the object taken was diminished, — it suffices to show its change of position. . ^ < . .. LENSES. 35 passage^ wliicli differs considerably in all sncb lknsks . media as the diamond^ glass_, water_, oil^ spirits_, air^ vapours_, &c. The nature of the refraction of Mature of rays of oblique incidence may be seen on looking at an oar in water^ or by allowing a minute sun- ray to pass through a hole and receiving it in a vessel of water^ the change of direction on its entering the fluid from air will be distinctly per- ceptible. In addition to this change in its Dispersion of course^ its incidence in the above conditions has dispersed or divided the beam into its coloured components ; the effect of this in lenses would be^ if uncorrectedj that each object would be seen surrounded by coloured fringes_, but as the refract- ing powers of flint glass and crown glass differ considerably^ the dispersed rays refracted from the one are re-united in their passage through the other, achromatism^^ results, and the coloured Achroma- tism. fringes disappear. This is the case in telescopes, microscopes, &c. ; Telescopes but as their application is intended for .scopes, alone, it is only necessary that their lenses should be corrected for colour^ ^ to such a point as to recombine the rays which form the image to the eye. * But the photographic lens differs from these in this important particular, that it is not ad- dressed to our sight, but to chemical action on the The pimto- , , , . graphic lensj film, part of which resides in a portion of the spectrum invisible to the unassisted vision. Not . 38 PRODUCING AGENTS. to include them has no effect on the perfection of the image in a telescope; to neglect including corrected for them all ill tlic photographic lens corrected for coincident ^ ^ x o j. foci; coincidence of foci^ is to retard and confuse its action in the proportion in which more or less of them may have been omitted. > If the lens is so constructed thkt the two foci not corrected are uot intended to coincide^ the nature of its for coinci- dence. action is as follows : the eye appreciates the picture as seen on the ground glass by the visual rays — the yellow ; but if the collodion film were placed in that focus^ those rays being a blank in photogenic quality^ the picture would be deli- Image drawn UCatcd by the actinic rays. by the actinic rays_, for which — being refracted further from the lens — the film would not be in true focus ; and the result would be con- fused and blurred. Therefore^ with this class of lens_j it is necessary to inspect the picture on the ground glass^ and afterwards to ‘^^turn out^^ the lens in order to place the film in the point of maximum actinism. The difference between the two methods of two methods, construction is this ; in the first the ivhole of the coloured rays are converged to one point_, and the image is formed on the film by their united action as white light ; in the other^ the red and yellow rays are entirely ignored_, and the film is placed in a point of the actinic portion only. knTvvheunot ppacticc it is fouud that a lens not coin- coiucideut. Difference between the LENSES. 37 cident in its foci requires turning out^^ more in lenses. projmrtion as it is approaclied to tlie sitteiq or as the entire aperture is used; and^ that^ as it is with- drawn_, or its aperture diminished; the difference between the visual and chemical foci is less till at a certain point in either direction — of distance or aperture — the two foci coincide. The reason of this is that the obliquity of the juteral rays diminishes; and thej?" become more Action of k- ” ^ _ teralrays; parallel and less dispersed as we retire; or by excising them by diaphragms they are excluded; and the picture being relieved from their con- ^fosing influence; is depicted by the action of the central rays alone; which pass through the lens in an^iofparai- a more homogeneous state of colour and unity of focus. The same action is sensibly felt in lenses coincident in both foci; although to an infinitely less extent. This is only according to the primary law of light; wdiich passes unchanged through a refract- ing medium; which it enters at a right angle; but which is more or less dispersed in proportion to the obliquity of its incidence. And; indeed; the principle extends beyond the mere instrument; the verv atmosphere surrounding us is every instant — Action on our , , atmosphere. from sunrise to sunset — acted upon in the same manner. This it is that gives the greatest pho- togenic quality to the vertical white beam of the midday suU; which; as he descends towards the 38 PRODUCING AGENTS. lensks. horizon, diminislies in proportion as his rays, the pSess^^ refracting obliquely through our atmosphere, dis- perse and colour more and more as he recedes from the zenith, until in the vivid reds and yellows of his setting glory he disappears. So when some sudden change takes place in the actinic power — as is constantly proved hy the camera without our being visually conscious of it — the nature of the light, as emitted from its source, the sun, remains the same, but within our atmosphere, or by the passing clouds or vapours near the earth, its beams are obliquely reflected or refracted, and for the moment dis- persed in rays more or less coloured and unfitted for our purpose ; the cause removed, actinism returns. Lenses con- Lcnscs ou both systcms — the coincidence and ijoiii systems, non-comcidence of the two foci — are constructed by diflPerent opticians of great celebrity, and opinions are divided as to which method ofiers — apart from convenience in focusing — the greatest advantages ; the system which combines the whole of the spectrum, including the rays of greatest actinism with the retardive portion — or that which ignores entirely the red and yellow rays, and placing the film beyond their influence executes the picture, by the action of a part only of the spectrum. The author^ s experience in practising Opinion on with both inclines him to prefer the coincident ties? lenses, as giving more equable results. LENSES. 39 The photographic lens varies in its construction lens es. and dimensions according to class of suhiect and^“.yT^t^ size of picture intended to he taken with it. treated. Lenses are either single or double combi- nations!^ The first are intended for pictures inanimate objects^ in the treatment of which the time of exposure is of no importance. Their focal length is greater than the double^ consequently, at the same diameters, larger pictures are ob- the double combina- tained. Double combinations differ from them tious, in having a second pair of lenses behind the first pair, which, intercepting the rays refracted from them, causes them to focus at about a quarter less than their former distance, whereby the action is accelerate , , - „ - . - - the action, accelerated, whilst at the same time the curves oi the back pair are so combined as to diminish the obliquity of the rays passing from the front ; thus the pencils are relieved from the confusion con- sequent upon dispersion and spherical aberration — both, as has been shown, attributable to defective parallelism — and thus purified in their action the Kefine the image. image they impress is more delicate in its de- finition and rotund in the appearance of the forms delineated ; whilst under these conditions of double correction the aperture which can be used is of much larger diameter than would have been possible with the front pair only, and thus the action which, to impress the same image, would com^^ative have necessitated an exposure of sixty seconds, is accelerated, and ten suffice. 40 PRODUCING AGENTS. Lenses. Various di- mensions. Size of result- ing picture. Some data of various sized lenses. Tlie double or portrait’^ lens is made of several diameters^ the smallest one IJ incb^ witli a focus of Tbe sizes then augment to 2^ 3^ 4y 6j 8 ; and Mr. Andrew Eoss_, the optician^ has constructed a combination of 12 inches. Besides the variation in diameter^ double lenses are made with the surfaces of their components more or less curved_, which causes the focus to be diminished or increased in its distance from the lens. This regulates the size of the picture which is given; thus^ 3-inch double combinations are made with focal lengths varying from 2| to 12 inches^ the first giving an instantaneous picture in the fraction of a second_, but of the limited size of 3| by 2| inches ; the second capable_, by a suppression of its lateral pencils_, of covering a surface of 10 by 8 inches in twenty seconds. The writer has an 8-inch Boss which covers a diameter of 30 inches in sixty seconds^ 2| front lens. A 6-inch Jamin covers a diameter of 20 inches in forty-five seconds^ 2g aperture. A 5 -inch Voigtlander covers a diameter of 16 inches in thirty seconds^ with 2-inch aperture. A 4| Boss covers a diameter of 13 well to the edge — published plate of Don Quixote. With 2-inch aperture takes a three-quarter portrait on 12 by 10 in twenty seconds. All the above in the most favorable atmospheric conditions. LENSES. 41 3-incli diameters_, by various makers become r^T^sss. more deep in focus in the picture_, and are rapid^ but cover less surface. The smaller sizes present infinitely less diffi- culties in every way^ but give only diminutive results. The peculiar differences arising between various Qualities arising from sizes and combinations^, apart from their perfect various sizes, construction^, are dimension of resulting picture^ time required to execute it^ depth of focus in the subject_, and quality of definition in the finished work ; all of which vary considerably according to the nature of the combination. The dimension of the picture arises from the nimensionof ^ ^ ^ the picture. diameter of the lens^ and with the same diameter^ is greater as the focal length increases_, and less as it diminishes. The time of execution depends upon the area of aperture_, compared with the greater or less focal distance from the lens to the film. Depth of focus in the subject is a most important Depth of j focus. j quality_, which diminishes in the ratio that the length of focus in the camera is increased. Quality of definition arises from several causes. Definition. Unskilful chromatic correction by the optician will cause the rays to overlap one another and confuse the image ; excess of spherical aberration will give a lens in which the centre and margins Eauit witii the optician j cannot be in simultaneous focus ; size of picture 42 PRODUCING AGENTS. Lensks. mtli the operator. Hovr to test a lens. attempted compared witli the reflexive area of the subject gives a weak image. Want of skill in the operator_, in approaching nearer his models and not cutting off the lateral rays^ gives distortion and confused deflnition. The small-sized lenses give images of greater intensity_, rotundity^ and freedom from distortion than the larger^ which demand all the skill pos- sessed by the photographer to prevent them be- coming defective in those qualities. The various sizes of lenses necessary to execute certain classes of subjects will be given in treating of each of them. The test about to be described will enable the photographer to decide^ at one and the same time^ the qualities possessed by a lens in all the above points. At one end of the glass room construct^ either with light wooden laths^ or strings drawn across between nails at regular intervals of some six, nine, or twelve inches, a flgure of the nature of the one given below; it may be either upright, square, or oblong. It will be well to suspend a large printed paper or poster between the points, 2, 2, on the cen- tral parallel line, and immediately in front of it a life-size bust ; much of the rest of the space may be filled in with a variety of objects of still life, taking care, however, not to hide the LENSES. 43 numerals. Now place tlie camera precisely op- posite to^ and at a right angle with the centre of rameS? the subject^ level it with a spirit level and fix it securely, use the full aperture of the lens, and Fig. 13. focus very exactly on the centre at 0 ; take the pic- ture, say in eight seconds with a 4 J, in five seconds with a 3J lens, according to light, develope it. If it is wished to compare a second or a third lens compnring of the same size, unscrew the first and replace it leilSsJ with a second — should it not fit the same flange, it will he necessary to have a temporary front slide made in common deal, — ^refocus on precisely the 44 PRODUCING AGENTS. Lensks. at full aper- tures, with dia- phragms. % The printed results, Of rapidity. Definition. same point in tlie subject; be as rapid as possible in manipiilatingj in order that the conditions of liglit may not yslyj between tlie tAvo pictures^ take it exactly in tlie same time of exposure. HaAung taken tbe results with full apertures^ it will now be well to place_, say 2-incb_, diaphragms in all the lenses^ wbetlier 3^ 4, 5_, or 6-incli diameters^ and take pictures_, giving, say, 15 to 60 seconds, according to tbe size of tbe lenses, and tbe state of light. Observe that all tbe conditions and mani- pulations must be as strictly as possible identical. Now, on printing tbe results, it will probably be seen that, even if tbe lenses were of tbe same maker, and of tbe same focal length and diameter, they may vary considerably in their qualities. That No. 1 in a 40 seconds^ exposm’e gives a perfect image, while No. 2 would have required 5 seconds longer; ergo, No. 1 is in 40 seconds, 5 seconds tbe more rapid. For clearness of definition look to tbe full aperture pictures, see especially bow tbe printed sheet compares in each and tbe rest of the objects seriatim. Flatness of field is what tbe numerals on tbe long central line will more par- ticularly decide; take tbe full apertm^e pictures and examine that line, see boAV far along it, from the central point perfect, or nearly perfect, defi- nition of tbe numbers is maintained, and tbe figure at which in each it becomes defective, and LENSES. 45 you may fmd tlie difference of flatness of field as l^wsrs. much as shown in the dia^u’am^ Fig. 14. 20 15 iO 5 0 5 10 IS 20 and that consequently b is the lens which is flatter in the field than c^ which would not only give it more correct drawings hut enable it to cover a larger surface. The depth of focus in the ueptiiof focus, picture will at once be shown by the numerals on the staff at right angles with the lens ; according as more or less of them are in focus from the central point 0 to 5^ front and bacJcj so is the action of the lenSj in this particular_, more or less perfect. In general^ in testing a lens_, far too much stress is laid on its power of copying a sheet of the ^ Times^ ! and the much more important quality — to its purposes — of depth of focus in the picture is overlooked ; the consequence is^ that when a 'portrait is taken with such lenses, a shal- low line of correct focus^ through the figure and drapery^ is in immediate contact with the most misty and distorted forms. Such lenses are ex- cellent for copying oil paintings^ &c. ; they have a large j flat field_, and^ for such uses^ the shallow- ness of their focal depth is of no consequence. 46 PEODUCING AGENTS. Eensks. The main object of a portrait-lens^^ is what Qualities ne- its name implies, and the qualities most requisite cessary to a ^ double lens. shouM possess for that purpose are — rapidity, depth of focus, and good definition ; the first and last go together, being both governed by the same cause, namely, the perfect concentration of the whole of the rays, including the lavender. Chromatic When by unskilful chromatic correction any of correction . . . defective, thcsc havc bccn omitted, their disturbing in- fluence — out of true focus — is felt in definition, and the lens, deprived of their actinic power, is Gives faulty slow in its performance. This mode of testing- definition, _ ® and slowness, their qualities applies equally to single lenses, but they have at the same diameters deeper focus, a flatter field, and give a larger but a weaker picture. Their appropriate sizes and apertures will be treated with the subjects for which they are used^as landscapes, copying, stereoscopy, &c. DIAPHRAGMS. diapheagms . Diaphragms, or stops, are metal plates perfo- Description rated witli a central aperture, ranging from ot. one eighth of an inch up to nearly the full diameter of double combination lenses. Their action They increase the clear definition in the picture explained. . . . . by their action on the marginal rays reducing the spherical and chromatic aberration, and they add DIAPHRAGMS. 47 to the focal depth in the subject; but for every piaphuagms. diminution of the diameter of aperture a corre- sponding reduction in the quantity of light which illuminates the collodion film takes place,, and there is,, therefore^ with the double lenses especially^ a limit of decrease of aperture which should not be exceeded, as otherwise the deposit of silver on Judicious ap- plication of. the glass will be too weak and inefficient to print well ; and as the time necessary to take the picture increases most rapidly 'pro rata as the size of aperture diminishes,, the artist must be content^ when operating from the life^ to sacrifice some portion of definition in his picture^ the better to secure a vivacity of expression in the counte- nance. Practice only will enable him to decide on the instant what aperture certain qualities of light,, subject, and lens will require, and beyond which point it would be objectionable to reduce it ; and the acquisition of this faculty is so neces- sary to the proper use of the lens, that I would advise the student to address himself diligently to Note care- the observation of the variations caused in the S\ts^ action of his lens by diflPerent applications of diaphragm ; to note the time of exposure, the conditions of light, temperature, bath, and col- lodion, under which the picture was executed, which experience alone will make him master of the variety of effects consequent upon the man- ner of working the lens with different apertures^ 48 PRODUCING AGENTS. PfAPiiRAGMs . according to liglit^ subject undertaken^ and quali- ties desired to be obtained in be picture^ — the im- portance of which study to a perfectly successful result cannot be better illustrated than by the fact that by skilful adaptation of his diaphragm one Greatly im- Operator shall^ with an inferior lens_, make a fair picture_, whilst the inexperienced will utterly fail with the most perfect instrument that the optician can furnish. Many works on photographic manipulations direct the diaphragm to be placed in front of the double combination lens^ and^ indeed_, arranged in that manner they have been always delivered by the first opticians. Operators are still found who neglect the benefit to be obtained by placing it in Their true its proper position. which is between the two position. X A X lenses. The advantages of which are_, that the spherical aberration is thereby reduced to a mini- mum_, that there is more depth of focus in the picture^ that more lights at the same aperture^ arrives to the film_, consequently that there is more rapid action_, and that from the same lens^ at the itsadvan- same area of aperture^ a much larger picture is obtained. More than a year ago the writer had extra apparatus made to his lenses for carrying the diaphragms between the combinations^, it being then quite unusual to use them in that manner. The great advantages which he found in the quality in working with them had one serious DIAPHRAGMS. 49 drawback;, namely^ that it was necessary to nn- diaphragms . screw and take the lens to pieces several times in inconvenient taking a portrait ; and this tedious and unnecessary manipulation had to be carefully gone through just when the whole of the operator’s attention was required to be devoted to his subject. The photographer should arrange his sitter and inspect Necessary to ^ tix or change his subject at the full aperture of his lens; he not only has more light upon the subject in the camera_, but the planes of perfect and of faulty focus are at once so defined^ that he is facilitated in improving the arrangement of his picture by advancing or retiring any portions of it. Having done this he must now, acccording to the exigen- cies of focus in the picture, and the quality that the light at the moment may happen to possess, for^the Ught arrange his area of aperture, on which in fact depends the definition and time of exposure of his picture. How is he to do this if a valuable instru- ment has to be taken in pieces each time to place the diaphagm required ? when at the same moment his light may be altering, and by the delay most certainly the expression of his sitter’s countenance will be deteriorating. The accompanying wood- New metiiod . - . of placing. cut Will show a diaphragm-holder invented by the writer, whereby any desired change, either for enlargement or diminution of aperture, may be added on the instant, or changed^ according to the option of the operator, and with the greatest i^s facility. 4 50 PRODUCING AGENTS. pr APHRAG^rs . facility. Fig. 15 represents tlie diapliragm partly drawn up in the holder^ in order to give a better idea of the mode of arrangement_, which is so contrived as to give the greatest rigidity to the tube of the lens^ although it is necessarily cut through for half its diameter ; at the same time; it allows the diaphragm to be placed or changed with the most perfect facility, and light to be totally excluded by the hinged cap being shut down ; the placing or changing occupies two seconds. Necessity of Notc, that tlic Icus must bc focused — with the focusing tubc — after the diaphragm is in situ and not hefore, as the length of the rays refracted by the lens varies with every alteration of aperture, being longer as it is smaller, and vice versa. We will now examine the variations which are caused by the position which the diaphragm oc- cupies relatively to the lenses, in order that the Eiir. 15, DIAPHRAGMS. 51 reader may clearly appreciate the differences between them. Fig. 16 represents a section of a 4 J -inch donble or portrait lens at its fall aperture^ witb tbe manner in wbicb tbe pencils of light from tbe subject pass through tbe combinations^ and are Fig. 16. refracted by them to tbe film. a is tbe fronts b tbe back lens_, c c tbe central rays^ e e tbe lateral ones ; tbe fine of focus at tbe film^ d will be ob- served to be curved^ and always is sbgbtly so^ even in tbe best-corrected double lenses^ when tbe full Ptaptiragms. Phnto^aphic lens Pit full aperture. Nature of its action. 52 PRODUCING AGENTS. Diaphragms . apertuTC of the lens is employed ; the consequence is that the picture is circumscribed in size_, and Its condi- that in proportion as it recedes from (c) the central rays_, imperfect definition becomes more and more apparent on the plane surface of the film. The attention of the reader must be directed to the width of the pencils refracted from the lens at Fig. 17. this aperture,, and the obliquity of the direction of altered by the lateral ones (e e), in order that he may obserye diaphragm. ^ ^ the changes which the application of a diaphragm will at once effect in them. Eig. 1 7 is the same lens DIAPHRAGMS. 53 witli thepencils of light drawn to scale; a diaphragm diaphragms. (d d) of two inches aperture (a) is now added between the combinations^ the effeet of which has SSue been to diminish the obliquity and give more parallelism to the rays proceeding to the film^ and more depth in the focus. On contrasting the width of the peneils e e with those in the last The changes , p , , it causes. diagram^ they will be found to be diminished m their diameter by one half^ with more delicacy of delineation^ but at the loss of rapidity of exeeution by the abstraction of a corresponding illuminating area. The length of the focal distance from the back lens to the film is inereased^ but with a well- corrected lens the field_, under such conditions of aperture^ is flat. We now pass to the seeond manner of plaeing the diaphragm — namely^ in/ro^/ of the lens. This mode Diaphragm in ^ ^ . . . front. is only good when eopying pictures_, prints_, maps_, and perfeetly flat surfaces is undertaken. It will be observed_, in the first plaee_, that the distance from the aperture (a) to the film is inereased by this treatment^ consequently that a longer exposure is required ; but the most important change is, that the diaphragm (d d) has entirely masked a con- siderable portion of the front lens ; in placing it between it will be seen, on referenee to fig. 17, comparison that was not the ease, but that rays from the me^thodl^ whole surfaee of the front lens were converged to the diaphragm ; this, of course, has a material 54 PRODUCING AGENTS. PiApn RAGMs. eflPect on the time in which the same lens^ in these two different conditions^, will take the picture ; for rig. 18 . the distance from the diaphragm in front (fig. 18) to the back lens being six and a half inches_, and the focal length thence to the film being fifteen^ it follows that the illuminating aperture was reduced to its minimum_, at twenty-one and a half inches Pictuie iu- from the collodion film_, whereas the distance from area. a to E, in fig. 17 ^ being three inches, eighteen DIAPHRAGMS. 55 inclies is tlie distance at wliicli liglit is first re- PrAPHBAGMs. stricted by diapliagm, so tliat a clear gain of three and a half indies, or more than one seventh of focal length, is established. The illuminated disc, given by the lens on the glass, is likewise increased ill size by placing the diaphragm between the combinations j in the lens in question one inch and a half was added to the diameter of the picture. Enough has been placed before the reader to show him that area oe aperture is the very helm importance 1-1 T • 1 1 1 1 • which regulates and guides the photographie ac- aperture, tion ; if too niueh diminished not only the time of exposure becomes irksome, and the expression of the sitter^ s countenance suffers, but a harsh and unnatural edginess characterises the picture. If, Decides the . qualities of on the other hand, it was allowed to be too great, the picture the oblique pencils, which it should have corrected, interfere with the perfection of the ima^e, and T^esuitofneg- ^ ^ ^ ’ lectingit, distorted forms and misty outlines are seen. So that as time of exposure and quality of de- finition are entirely dependent upon the proper use of the diaphragm, the necessity of carefully studying its varying action will be apparent ; and so altering the size of aperture, as may be most appropriate to the circumstances of light, size of reflecting area of subject and distance of the lens from it, that not one pencil of light shall be sup- pressed which could contribute to forming the 56 PRODUCING AGENTS. diaphbagms. image correctly, nor any allowed to remain which, by their obliquity, would distort or confuse the Scale of dif- ferent dia- picture, meters. ^ The accompanying scale will assist the student Fig. 19. in comparing, with sufficient precision, the dif- ference of area from one sized diaphragm to another, and basing his calculations for time of exposure accordingly. PART II. THE REQUISITE APPARATUS. THE GLASS STUDIO. In taking portraits of any size^ or arranging glass • Studio. groups from tke life^, no good results can be obtained in Pliotograpliy^ uiib cuted in a glass room or studio^ with regard to the requirements of the process^, as the least wind deranges the hair of the sitters^, and the ribbons_, folds of draperies^ &c._, of their costume. In other respects^ the necessity is detrimental but dimi- nishes light. to the photographic action_, since all glass gives a greenish tinge to objects placed under it. We have only to compare the faces of persons stand- ing under the first railway station with those outside^ to feel convinced that such is the case. We will now consider what are the desirable SS they are exe- Necessary in . portraiture; specially designed 58 REQUISITE APPARATUS. s?uDio conditions of aspect^ form_, and size_, wliicli liave to be stndied_, as being tlie most favorable for the purpose. Its proper A locality open from N.E. tbrongliN. to N.W. ^ is the best, taking care that the light is not masked by high buildings towards those quarters, but that, if possible, it is uninterrupted from the zenith to the horizon, which will give the operator the power of using it at such an angle as may best suit the subject he may be treating; and modifying, by blinds, the greater or less degree of intensity of light on the features of his sitter, according to circumstances. Improper No arrangement of blinds can, by any possi- bility, give an equally favorable result, should the glass studio, instead of facing the more even moderate light of the aspect above described, be erected facing the south ; the disadvantages being, that the light is too powerful and most uncertain, and, owing to the passage of clouds before the from its va- Rud from the changes which take place in ' the light on the sitter, from one second to another, it becomes impossible to calculate with the requisite accuracy the time of exposure ; moreover, the potency of the light approaches, in some degree, the effect of the direct sun-ray, and the picture is likely to be harsh and dis- cordant ; black shadows and rocky white lights taking the place of the more delicate gradations GLASS STUDIO. 59 in both^ which should have been seen^ — indeed, glass Studio. in every way a south aspect is to be avoided. The size of the building will of course greatly size of the studio = depend upon the class of pictures which the pho- tographer proposes to take in it. Groups of numerous figures_, full-length portraits^, with acces- sories_, executed with large lenses_, will naturally require more spaee than works of less dimensions^, Regulated by iiatui-e of such as single figures and small portraiture — for subjects, the first_, fifiy feet by twenty-five_, forty feet by twenty^ or thirty feet by twenty^ will not be too large ; for the second, twenty feet by twelve, or fifteen feet by ten, will sufiice. The slope of the glass roof should be so arranged that at the part where the sitter is plaeed the light may be incident upon the subject with the least disturbanee of its components ; an angle of forty- five degrees, if the angular form of roof is used, will Best form for its roof, be the best; but if the extra expense is not an object, much better results will be obtained from the adoption of the half-cylindrieal form — as the writer^s experienee of the qualities possessed by two glass studios, in identical aspect and in juxta- position, but of the two forms in question, leads him to give greatly the preference to the eireular, circular; as possessing more evenness and greater rapidity under equal conditions of light. It may be ac- counted for in this manner — owing to the con- tinual variation in the position of the sun, it is 60 REQUISITE APPARATUS. ^glass not possible to adjust tbe angle of the straiglit- sided glass roof in such a manner that the light incident f^ht angles, and with the least dis- turbance or loss of a portion of its power; by the obliquity of its impingement on the glass; it will, except at one particular interval, be inci- dent at an oblique angle to the glazed surface, either as at a or b, and thus suffer a derangement or loss of some portion of its actinism, which is probably the reason that in practice the quality of light is found better which has passed through a circular form of glazed surface, which always pre- sents the same conditions to the incidence of presents the the luminous principle, whatever may be the same condi- tioas to every angle at wliich it impinges upon it, as at a, b, c. The colour of the glass used for this purpose is Fig. 20. fig. 21 GLASS STUDIO. 61 of the utmost importance^ the retarding influence glass Studio. of greenish tones in the ordinary glass being very ^ great. An extra outlay for perfectly colouidess Fig. 21. c sheet glass, which is now manufactured, will amply repay itself by the increased rapidity with which pictures can be produced — the advantages to be gained, where portraiture is intended, cannot be over-estimated. The means of diminishing light, when in excess. Arrangement by white blinds, should be arranged ; they should be fixed half from above and half from below, from the eaves and the ridge of the roof, thus giving the power to the operator of not only regulating exactly the quantity but the angle of light used to the subject, from about twenty to sixty degrees, as may seem best to him. The floor should be con- structed with the greatest care and solidity, many failures arising from the tremor imparted to the camera by movements across a weak floor, and which are increased in their detrimental effect in 62 REQUISITE APPARATUS. Glass STrcro. Colour of walls, and carnets, &c. Its tempera- ture. Removing cameras and chemicals from it. Polished sur- faces detri- mental. proportion as tlie camera is raised in height from it. The walls should he distempered or hung with papei% in which greys^ hlues_, violet_, bluey greens^ or white are the only colours — or one or other of them at option — avoiding strictly pal terns in which yellows^ yellowy greens^ reds^ or browns appear ; which must also he considered in the car- peting or drugget ; an uncovered deal floor gives^ when new^ very pernicious reflexions. Such a room will he found extremely variable in its temperature^ in excess of heat in summer and of cold in winter; ventilation at a high level, and arrangements for warming, by hot- water pipes or stoves, must be provided ; and from this quality it is obvious that the cameras should he removed after use, in order that they may not he rendered inefiicient by the warping and derangement of their parts, and that no chemicals of any descrip- tion should he kept in any part of it. It will he necessary that no considerable var- nished or French polished surfaces are in it, since the reflexion which they would give might occur in a manner to derange the light and shade on a sitter, and the vicinity of any bright or glittering objects would he seriously detrimental in copying oil paintings. It is of great importance that the glass studio should he in as immediate contiguity as possible to OPERATING ROOM. 63 tlie operating room^ as thereby delays are avoided^ gi,ass wliicli in warm weather may have damaeinoc ® ° Its continuity results, in causing: the collodion film to lose ’ o ting room. sensitiveness. THE OPEEATING EOOM. A little contrivance and knowledge of the opekattng requirements vEich have to he provided for^ will make the difference between an inefficient black armngeA hole,, and a room in which the operator can work with celerity and certainty. Small and inconvenient dens may be made to do duty on occasion j but if it be possible to obtain a certain space^ say sixteen feet by twelve, for the purpose, it will be well bestowed, both in the increased convenience for the production of the negatives, and for the health of the operator, by the superior ventilation it affords. The aspect should if possible be N.E., to avoid its aspect, the direct rays of the sun upon its yellow blindages; the window should be glazed with yellow glass, by the light transmitted through which paper may be excited and bath solution prepared; but in operating for the camera, a curtain of two or three thicknesses of yellow calico in addition will be Teiiow light alone admit- found necessary, according to the greater or less ted. sensitiveness of the preparations. 64 REQUISITE APPARATUS. opebating The room should have a fire-place for warmth Room. Meaiis of wlntci^ aiid ventilation^ or drying of excited iieating papers; and if there is a small boiler for hot water Fig. 22. 1. Developing sink. 2. Sink for washing negatives, with gas, and water laid on. 3. Cupboard for chemicals. 4. Arnott’s ventilator. 5 5 5. Shelfing. 6. Air-shaft. 7. Rack for trays. 8. Door into glass studio. to the stove,, it will be found advantageous in a variety of manipulations. A large Arnott^s ventilator at the top of the OPERATING ROOM. 65 room in tlie and an air-shaft^ not admitting operating lights with small flap doors to close when desired^ at the level of the floor^ near the developing sink^ will assist to carry ofP the fumes of the chemicals. Two sinks lined with gutta percha, with waste- operating pipes of the same material^ should he fitted entirely separated^ from each other; one for developing the picture^ the other for standing the negatives in to steep in water, which should he laid on with "^ater and . . . several taps to both sinks. Gas likewise should he fitted along the sinks with deep yellow glass chim- neys to the burners. Shelves for bottles, and a sheifmg. well-made close-fitting cupboard for chemicals, are cupboard for wanted ; at the same time it is especially advised not to make the shelves of the dark room recep- tacles for all the nameless rubbish apt to accumu- late in such a locality, and thereby establish dust- traps to the certain deterioration or destruction of future pictures. Let the dark room only contain those things which legitimately belong to it ; let the shelves, &c., be washed frequently and kept free from Necessity of dust, the sinks in the eleanest condition, and the cleanliness, floor covered with oilcloth, as being the material with the most unbroken surface and most easily purified from dirt. It is imperatively necessary that not the slightest gleam of white light be allowed to Precautions against wbite penetrate into this room whilst operating ; plates 5 66 REQUISITE APPARATUS. Opkeating Room. Lead detri- mental for sinks, pipes, &c. Camkras. Annoyances if badly con- structed. may be spoiled one after tbe other by a half open keyhole opposite them when draining, or by a forgotten cranny at the bottom of a door. Curtains to remedy this are not proper, they accumu- late dust in their folds, and the movements on drawing them disperses its motes through the air of the room, to settle ultimately on the film ; if the doors are leathered round it is quite as effectual in excluding light, and more cleanly. Note, that if lead linings or pipes are used for the sinks, they will be acted upon by the chemicals, they will soon be full of holes, and the vapours of their combined action are most unwholesome. ON CAMERAS. In selecting a camera it is necessary to see that it is of the best quality, both in seasoned material and good workmanship ; otherwise the patience of the operator will be severely tried, if his picture be not spoiled, by slides^ ^ which will not stir, and moveable bodies’^ which are obstinate fix- tures j and by light — which in photography must be regarded as a destructive as well as producing agent — finding its way to the film, through many apertures besides the lens ; these tribulations CAMERAS. 67 generally happening when some subject more cameras . important than usual is under treatment. Cameras vary considerably in their make, ac- cording as they may be destined exclusively for portraits and groups of figures in the studio, or being intended for landscape and out- door work, are made to fold together and be as portable as possible. Considerable ingenuity has been shown in the adaptation of all photographic apparatus to the purposes required, and in none more than in the manufacture of cameras, which have been constructed in so many ways, that the beginner may be puzzled to make his selection. I would advise him to eschew all idea of the purchase of a cheap or foreign one, as generally they are made and quality, of ill- seasoned wood, and are of inferior work- manship, in which a straight line appears to be the exception. It has been customary to make cameras in the form of a parallelogram, so that if the operator wishes to make an upright picture, he has to fix the camera on its side, which is most objection- ohiong able, since not only are the difliculties of manipu- lation much increased, by the slides having to be worked from the sides, and never moving readily in such position, but the camera cannot be per- fectly and immoveably fixed, and a confused pic- ture is the result ; all which, and the consequent vexation and loss of time, is obviated by pur- 68 REQUISITE APPARATUS. CAMEKAa, Sqnare tlie best. Portrait camera de- scribed. chasing a camera of a square form^ in wliich^ by means of inside frames^ pictures of any shape and size_, within its external dimensions^ may be executed. It will be unnecessary to describe many forms in which cameras are made j the smallest sizes are very simple and inexpensive ; of the larger descrip- tions^ fig. 23 represents one of the best arrange- Fig. 23. ments for portraiture_, inasmuch as its construction with two sliding bodies permits lenses of several focal lengths to be conveniently used in it between the distances of six and twenty inches ; it has sliding fronts which allow the lens to be placed in any position within the field ; it has a double swing back — which all portrait-cameras should have — to allow a slightly inclined position to be given to the collodion film in subjects of difficult focus^ or CAMERAS. 69 when ^^short-focused'’ lenses are em|)loyed for cameeas. children^ &c. For landscapes, out- door work, or foreign travel, greater portability than the above is requisite, which is best obtained by the ‘‘folding- sliding” construction, which, when packed, lies in Fi^. 24. the compass of the first light line from the bottom described, in the woodcut. Here again, arrangements should be made, by the rising flaps shown, to allow a diversity of lenses to be used. As it is desirable that several lenses should pass the same camera, it should therefore be made of sufficient length to suit the one of longest focus. The means of chanffinff them with ease and^eansof ° ° changing the rapidity is to have brass collars, called by the^^“®^®- opticians “ adapters” which screw into the front of the camera, and thus make up the difference between their diameters. 70 REQUISITE APPARATUS. Cameras . Desirable size. With its lenses. Tests of its perfectness. in different qualities. An excellent size_, for general purposes^ is a camera with twelve inches square hack and about two feet long; it is convenient^ and portable^ and can he used either for small pictures or at the fall dimensions. If such a camera he furnished with two portrait or double lenses_, of the diameters of about five and three inches^ and two landscape- lenses_, of about three and a half and two inches in diameter^ the purchaser, if the lenses are well selected, will possess, in this department, a most satisfactory apparatus, and one well fitted for all purposes. Having procured the camera, it will now be necessary to test it for two qualities ; first, its im- permeability to light. Withdraw the ground glass, and covering the head and shoulders very completely with the focusing cloth, the lens having been capped, look into the camera and examine well for any crevice through which light may come ; if none is seen it is perfectly sound, and the greatest aim must be to keep it so. Now test it to see that the inside of the focusing glass and the film side of the glass in situ in the slide accurately correspond. To do this focus carefully on an object with the full aperture of the lens, with exact precision, and take a small picture ; if that object be not in the best focus of the negative, either the chemical and actinic foci of the lens do not correspond, or the construction CAMERAS. 71 of the camera is defective^ and the ground glass cameras. and collodion slide do not agree. Whatever skill may have been shown in the perfect construction of the camera^ do not for a moment suppose that it can keep out bright sun- shine when full upon it out of doors ; under these Careful usage necessary. conditions it must he rigorously kept covered with a thick haize^ and the collodion slide should also he wrapped up in transitu backwards and for- wards to the camera^ and the cloth cover kept over it in drawing up the flap. Never let it stand in the sun, no wood can resist that ; nor in a draught between open doors and windows; its parts are thin and delicate, and will warp by such usage. Let it he removed, immediately after operating, from the glass room, where the variations of heat and cold are great. It should he covered with a j^ature of thick wooUen baize, and it and the collodion hack should be well blotted from bath drainings as soon as study is finished. As before mentioned the contrivances for cameras are very various and numerous, but, provided the workmanship is good and the material seasoned, the more simple the arrangements the better. With respect to the cameras necessary to exe- cute the Stereoscopic picture, it has been thought better, as they pertain very entirely to the dif- ferent modes of treating that subject, that the stereoscopic .. .. T.-i 1 1 1 cameras. description ot the varieties which may be employed. 72 REQUISITE APPARATUS. Cameras. Camera Stands. Their forms if portable. Liability to accidects. Portrait stands. according to the nature of the work undertaken — or the number of pictures simultaneously or suc- cessively produced — should accompany the section Stereoscopic Pictures/^ as more necessary to its clear elucidation. CAMERA STANDS. In order to place the camera at a proper height and position opposite the object proposed to be copied^ it is fixed on a stand; these are usually made of a tripod form_, and are very various in their construction^ according to the size and weight of the camera they are purposed to carry, and likewise whether intended for landscape and out- door work, or exclusively for use in the studio. The first are so contrived as to fold together and take the least possible space, but are not well adapted to carry cameras of large size, and even with the smaller sizes are very apt to upset by the overbalancing of the camera, the sway of the legs at the joints, or the action of wind; they will require precaution on the part of the novice to guai’d against these accidents, which are very damaging in their effects both on camera and lens. Those intended solely for working at home in portraiture, &c., are of a more solid construction. CAMERA STANDS. 73 which prevents their heine: liable to the inconve- cameka ... Stands. niences above described : the chief points to study in selecting are the power of placing_, with the utmost facility_, the camera at such height^ distance^ and inclination to the sitter, as the nature of the Qualities necessaiy. subject may require; and that when placed the camera may be so solidly attached and held^ that not the slightest tremor is felt by it. These points Fig. 25. Fig. 26. Fig. 27. have been found in practice, by the writer, to be preferaWe very well provided for in the stand represented at fig. 26 . There is a rack- work for raising and lowering, and screws to fix it when at the required 74 REQUISITE APPARATUS. Cameea Stands. Safety of large. Swing Back Perfect com- mand of po- sition neces- sary. How ob- tained. elevation ; the castors allow it to he easily moved backwards or forward s^ and the camera may he dipped as required by the movements of appro- priate screws. The security and comfort in working is so great with the more solid stands^ particularly with large sizes_, that wherever practicable the student is advised to give them the preference in all sub- jects where the transport of them will not he found too inconvenient. SWING CAMEUA BACK. In operating with the portrait- camera it is most necessary to have the means of advancing or retiring it from the sitter_, of raising or lowering itj of placing the centre of the lens opposite any portion of the field which may he desired^ and of changing the position of the film from the precise vertical into such deviation of angle^ laterally and vertically^ as may best enable the action of the lens to coincide with the lines of the subject undertaken. All these movements are provided for by various ingenious contrivances ; castors^ and rack and pinion movements on the stands moveable camera fronts_, with double action^ to hold the lens and swing hacks to carry the film^ allow the opera- SWING CAMERA BACK. 75 tor to alter die distaiiee and position of tlie field S^VINOlUCK. as may seem most desirable. The aetion of the swing baek is intended by its motions to neutra- lize the distortion whieh results in using lenses of ^ commeuded. very short foeal lengths^ but it will also be found available and desirable with all double eombina- tions. Its aetion is illustrated in the eut. Fig. 28. On focusing any subject in which the lines are inclined from the direct vertical, as in sitting figures, &c., it will be found impossible to bring the lower projecting portions, as at a, into its action . - . . explained. locus With tlie upper retiring parts at b. Now, if the position of the film is judiciously altered by means of the swing baek, the portions defective in focus will be seen to assume equally correct de- finition with the rest of the subject. This treat- 76 REQUISITE APPARATUS. Swing Back , ment also applies to subjects in wliicb one or the other side is nearer to the lens, by slightly alter- dmTtdZms lateral distances both sides come in focus, movements, Operator can avail himself of both these move- ments simultaneously. HEAD RESTS. Head Rests. Unfortunately in photographic portraiture it is not possible to dispense with the use of this ad- junct, which if not used by the operator with the Adisadvan- greatest tact will infallibly tend to give a con- tageous ne- ./ o cessity. strained attitude to the portrait — the best, indeed the only way to use it properly, is to let the sitter go into a natural position of the body and head, and then gently to advance the crutch until it just touches him. The writer was long much annoyed in standing figures, by the sway which there was in the body, which, although the head was sup- Ponn of, for ported, occasioncd a doubling of the lines of the standing figures. hands, figure, &c., more or less according to circumstances. In large portraits this is of con- siderable importance ; as in these both the time requisite is longer and the movement more de- fined by the lens ; if, on the other hand, the sitter makes an effort to maintain perfect quiescence, that alone gives rigidity to the pose. To obviate HEAD RESTS. 77 these inconveniences the form of head rest, fig. head rests . 30, has been found very satisfactory. The stand is made of three-inch deal, also the strength 29. Fig. 30. Fig. 31. upright, vrhich is morticed into it. Strong angle and rigidity, pieces of iron are screwed on each side, and a T piece behind ; a small cushion is firmly fixed for the back, and a short bronze head rest, moveable by screws, is fitted on the top. It is entirely free 78 REQUISITE APPARATUS. Head Rests , from vibratioiij and the sitter/^ merely standing against it, can turn in any direction and change his position as required. pSitio^s”^ For sitting figures fig. 29 will be found more advantageous. It stands in any required position behind the sitter^ and its adjustment is regulated with great facility. The one represented in fig. 31 is made in wood^ and is intended to attach to the back of a chair : it has the advantage of cheapness^ but is very disappointing compared with the last. Sitters in general disclaim all necessity for the employment of the head rests, and are con- fident in their powers to remain perfectly im- moveable the operator must not on that account discontinue its use, as failures and loss of time are Injurious the inevitable results. Still, as was before inen- qualities. tioned, the head rest, injudiciously employed, spoils many pictures, often giving an air of leaning or constraint which it should be the business of the artist to avoid. ON THE GLASSES. <^lasses. Patent plate glass is the best to use for photo- graphic purposes ; it combines the advantages of Desirable flatness of surface and a high polish, both most piopeities. qualities to enable the collodion to flow GLASSES. 79 over it evenly and rapidly. Tlie numbers 2^ 3^ glasses . 4 (trade mark)_, being of different thicknesses^ Different thickness, these may be ordered^ increasing pro rata in thickness with the size of the plate^ thus sparing unnecessary bulk and weight in the smaller sizes^ and giving more strength to the large. It requires to be properly and skilfully cut^ as ^usthe care- if carelessly done the operator will_, from the same parcel_, have some which will slip through the frame, and others which will not go in. They should be set on edge and rigidly gauged to avoid such annoyance, which generally happens when it is of most importance that it should not. The first thing to be done is to roughen the Edges pre-> edges, which prevents the collodion easily running over the plate, in inexperienced hands, and enables the film to resist better the action of the water which it is necessary to pour over it, and it likewise prevents it from contracting at the edges. The witer has always done this by the applica- Mode of tion of emery cloth, which, if neatly manipulated, will at the same time take off the cutting edge of the glass, and leave a band of ground glass, some one eighth of an inch wide, on the margin of its top surface, to which the collodion film will firmly adhere, and which will save many disappoint- ments. It now remains to render the glasses perfectly 80 REQUISITE APPARATUS. Glasses , and cliemically clean. Tlie writer lias tried many of the recipes proposed for this purpose ; he has Care in clean- had hoth haths deteriorated and plates spoiled by the obstinate adherence of some particles of Tripoli or other powders to the edges of the glasses^ and has therefore discontinued the use of anything more than abundance of pure water^ running from a tap^ and a clean coarse linen rag to rub the glass with at the same time. Me when Stilly as soap is used by the glass-merchants to mark the dimensions^ &c._, of their plates^ it is a good precaution to wash the new glasses in a solution of common washing soda and warm water ; and if they have been previously used they should When used \{q for six hours or so in a strong solution of previously. ^ caustic potash^ with thin slips of firewood be- tween each, to ensure their surfaces being acted upon by the solution. Manner of After wasMng under the tap they should not be put to drain, as even in drying thus they may take cloudy marks difficult to get ofi*; but as each is perfectly washed it should at once be dried off with clean linens and carefully put away for use ; they should be packed in dozens, standing verti- cally, in new blotting paper, and not siifiered to come in contact with brown paper; nor should they be put in racked deal boxes, as they are sure Howtopre. to be acted upon at the edges in hot weather, by the contact of the terebinous wood, to the mani- GLASSES. 81 fest deterioration of tlie subsequent film and glasses. nitrate bath. Indeed^ even if packed for some i^iecautions. time with clean blotting paper between each_, held sideways to the light and breathed upon_, the form and texture of the paper will appear upon their surface, so that it is not safe to operate upon any glass that has been long put aside, the better plan being to have it fresh washed for use. Of course, the impurities of a London or town at- Atmospiiere of towns. mosphere are prone to condense on the cold polished surface of glass, and the photographic glasses should therefore never be allowed to remain exposed to them. The cloths which are used to wipe these glasses Giass-ciotiis. should be of linen free from fluff ; old table-cloths cut up well for the purpose. They should never be allowed to come near soap — they should be steeped in warm soda and water, rinsed abun-Modeof dantly in many waters, and hung up to dry, re- moved from all impurities. They should be well- aired, to avoid mouldy action, which is chemically deteriorating, and kept in well-closed drawers for use. In proportion as the summer advances the difficulties of the photographer with his glass plates progress. The hands of his assistant will contaminate the cloths with the impurities of the skin, and from thence result the long smeary other pre* . . cautions. marks across the picture. Have six or twelve 6 82 REQUISITE APPARATUS. Appakatus. Damp at- mosphere. Silver wire. Advantages. pairs of large common white cotton gloves^ chemically clean^ and^ by a proper use of them^ these annoyances will be avoided. Just before wanted the glass is to be polished ofiP with wash leathers or old silk handkerchiefs_, prepared as the cloths. If the day is damp it may be held for an instant before a fire_, but not long enough to warm it^ which would act upon the collodion ; if the atmosphere is dry^ it is not neces- sary; all that is required is to lose no time, as vapour of the breathy &c. may condense on its surface_, but when it is finished polishing proceed at once to lay the film. DIPPEES. The best dipper is a piece of pure silver wire, bent in this form, and where required to be joined. Fig. 32. which should be at a, not at the lower end, riveted not soldered. It has several advantages. Its first and greatest, that it never breaks and disappoints the operator at home; or, what is worse, on a remote journey. SCALES. 83 The jar of the metal against the bottom of the glass appakatus. bath is less likely to crack it than the glass dipper would be ; the plate neither slips oflp^ nor in larger clean eon- . . dition. plates annoys by obstinately adhering to the dipper : it is cleaned with the greatest facility. It should be washed immediately after operating, wiped with a chemically clean eloth; if used in a slovenly manner it will turn blaek and be deterio- rating to the bath solution. (Note, be sure that there is no alloy in the silver wire.) The ordinary glass dipper is obtainable every- Glass dippers where. SCALES Of some size, to weigh hyposulphite of soda, &c., in larger proportions. (These should have removeable coneave glass disks to place in the with glass metal pans, whieh preserve the chemieals from contamination by contact with the brass.) Box OF Scales, of less size, with glass pans, to Precautions, weigh the smaller quantities of chemieals, up to one ounce. (Note, that great exactness and ^^Ss neces- cleanliness are necessary in using these scales, as a small portion of pyrogallic acid, &c., adhering to them would suffice to spoil entirely a nitrate bath solution. When weighing out crystals of nitrate of silver, &c., it is well to cut two small squares of filtering paper, of precisely the same size, and place one in each scale.) 84 REQUISITE APPARATUS. DEVELOPING STAND. The usual and best form is the tripod, which is more easily adjusted to a level, by means of its screws, than the square ; it is well to have two The best sizes for different dimensions of plates. torin. ^ Fig. 33. To adjust it place a glass on the screws, and on it, as shown in the cut, the spirit level ; having centred the bubble^^ in one direction by turning the screws, alter its position to the opposite angle. Mode of level- The level is not perfectly attained until whichever way it IS turned on the glass the bubble re- mains stationary in the centre. (Note, that it is necessary to the even flow of the developing solution that this should be accurately regu- lated.) SPECIFIC GRAVITY BOTTLE. 85 PNEUMATIC PLATE HOLDER. This ingenious little instrument can be pro- apparatus, cured at any of the vendors of photographic appa- ratus^ it has the advantage of leaving the edges of the glass plate entirely free from contact^ and consequently the collodion from contamination; motion is communicated from the centre, as from a pivoL and change of level is given to the plate in laying the film with greater convenience than in other methods. SPECIFIC GRAVITY BOTTLE Should be in the operating room of every photo- grapher, since without it he will be unable to its use ne- cessai’y. know whether many of the chemicals he employs are of the degrees of strength and purity it is requisite they should be; as, for example, the alcohol absolute and washed ether, which are in daily use, for adding to the thickened collodion, and likewise for testing other chemicals. This bottle is of a globular form, with a per- forated stopper, through which the excess of any liquid passes when the bottle is quite filled, thus its nature; ensuring exactness in quantity ; there is a weight which exactly counterbalances the bottle itself. 86 KEQUISITE APPARATUS. Apparatus. The dimension is adjusted to contain precisely 500 grains of distilled water; if now the bottle be filled with alcohol absolute^ which at 60° Fahr. is 0*794^ or newly washed ether^ which at the same temperature^ barometer at 30°, is 0*725, on weigh- ing, the contents of the bottle will show a result in grains which, multiplied by two, gives the specific gravity. GLASS BATH. Used for m- To coutain the nitrate of silver solution nothing trate batk. ^ ° can he ^depended on, for chemical purity, but glass ; heretofore the glass baths have been made up^^ of several pieces of plate glass cemented together with marine glue, and much disappoint- ment and annoyance have continually been expe- rienced by their leaking, and the separation of their parts. Now solid glass baths are made on the Continent, which oflPer every advantage ; they can be obtained to take plates up to the size of To be eighteen by fourteen inches. It is advisable to stien^tkened. several layers of brown paper well saturated with paste round them, which, contracting as they dry, adhere intimately to the bath, and thus form a strong pasteboard case, which supports the glass, defends it from injury, and keeps light from the solution. WEDGEWOOD TRAYS. 87 WEDGEWOOD TEAYS Should be used exclusively for albuminizing and Apparatus . preparing plain paper, and holding the toning luUons. and fixing solutions; but those once taken for the two latter purposes should o?i no account be afterwards put to any other uses, since the nature of hyposulphite solutions is so searching that they traverse the entire structure of earthenware, as may be seen by filling a jug with them, — cottony effiorescenee and crystals will soon form on the outside. Neither are these trays capable of resisting the action of the sixty- grain nitrate solution used in exciting paper, which should therefore only be put in a glass tray, as described. They are the cleanest and most satisfactory for steeping the proofs in water after they are toned Used for ~ ^ steeping th.e and fixed ; it is better not to have them too deep, and overcrowd the proofs, but to use more of the shallower ones, and thus separate them more eflPectually. The number and sizes required de- pend entirely on the nature of^ study undertaken. GuttaPercha Trays have the great advantages Advantages f»Ti 1* • n 11 1 disad- 01 lightness and immunity from breakage, but vantages, are not proper to use for the exciting or toning solutions, since they impart an indelible though slight tinge of brown to the paper. They can be used with albumen, and to steep the proofs in water if desired. 88 REQUISITE APPARATUS. Appahatus, Some quan- tity requisite. Precautions to be ob- served. Of glass, and gutla percUa. DEVELOPING GLASSES, &c. Tliree dozen in three different sizes will be found convenient, and save much confusion in operating. They should be selected with rounded form of bottoms, to facilitate perfect cleaning, also the punty marks^^ ground off and bottoms polished. Glass Pestle and Mortar — ^is useful in re- ducing crystals to powder, and thus prepared they can be dissolved more readily when the operator is pressed for time. Graduated Glass Measures — 1 quart, 1 pint, I pint, 2 ounce, 2 drachm, 60 minim. These measures and glasses will require great care in cleaning, that no trace be left of any solutions previously prepared or used in them, as a slight contamination of one by another would have serious results. The cloths used should be chemi- cally clean, as those used for the glass plates. Glass Spoons — are very useful in manipulating crystals of nitrate of silver, pyrogallic acid, &c., thus avoiding contact with the skin. Glass Stirring Eods — of different lengths, for solutions (those used for nitrate bath solution to be kept strictly apart). Funnels must be of glass, and kept strictly separate, for the nitrate bath solution, and for the developing, exciting, and toning solutions. Two or three of gutta percha are useful for other purposes. RETORT STAND. 89 Thermometers are very requisite^ both in the AppARAxrs. operating room and glass studio^ in order that the photosrrapher may observe the temperature, The exact ® ^ temperature and take means to equalize it as mueh as possible, ^’equired. by the use of blinds, evaporation, ventilation, &c., in summer, and stoves and hot-water pipes in winter; and that knowing the precise degree, he may arrange the strength of his developer, and make necessary calculations respecting time of exposure, &c., accordingly. EETOET STAND Is of great convenience when preparing solu- used in fii-j tions, to hold the funnels as shown in the^^ ”^°’ cut, thus avoiding ac- cidents in the upset- ting of the bottles, &c. When filtering into measures it becomes indispensible, to avoid personal attention. In fusing any che- micals, and in various experiments connected with Photography, the retort stand will be found very useful to the practical photo- grapher. 90 REQUISITE APPARATUS. HORN TONGS appa ^tus. necessary to take hold of the corners of the paper in albuminizing^ exciting^ toning, and fixing ; not only because contact with the fingers solutions. leaves stains on the paper, but also that to immerse them in solutions containing particles of metal, most minutely divided in hypo- sulphite of soda, as in the two last, is decidedly deleterious to the operator. Care must be taken to keep a pair for each purpose, and that those intended for nitrate of silver solutions are sepa- rated from those used in hypo solutions. GLASS BOTTLES. To select the proper descriptions, according to the uses for which they are intended, is of much more importance than might appear. There have Glass bottles been scvcral collodion bottles contrived, some with for collodion ; ^ a view to straining or filtering it from the de- posit by percolation through sponge. &c., &c., but, no method for keeping collodion in perfect order for use is equal to the simple one of having one their form, stock bottlcs. The prcssurc of the column of collodion carries to the last half inch of the bottom all flue, dust, and fragments of dried film, which are very destructive agents in producing blemishes on the plate. It is easy to GLASS BOTTLES. 91 decant gently from tlie upper portion into a appabatus. smaller size for use^ keeping the stock bottle re- plenished as may be requisite ; the same treat- ment is equally necessary to be adopted with the varnish. In order to appreciate the degree of failure avoided by these precautions it is only necessary to lay a film^ or varnish a plate with the lowest strata of either bottle. For works of any size,, 20-ounce tall stock and size bottles,, fourteen inches high^ are not too large,, — 12-ounce for smaller sizes,, &c. In laying the film,, 6-^ S-, or 12-ounce,, two thirds full, are good sizes; smaller bottles are convenient to preserve odds and ends of collodion^ which all have their uses in the treatment of various subjects. Observe^ particularly, that the stoppers of these bottles are well and evenly ground in. Ether, for the bath solution, and alcohol abso- etiier and ^ ^ ^ ^ alcohol; lute, require capped bottles, and it is better that they should not be large, since when a large bottle is only half or one third full, the remaining por- tion is filled with atmospheric air, which deterio- rates both the above, which are required in the tiieir requi- sites. utmost possible state of purity. Instead of one^ it is better to have four or six smaller, carefully tied up and capped, to open as required. It will spare the chemical cupboard from unpleasant fumes if the use of capped bottles be extended 92 REQUISITE APPARATUS. appaeatus. to nitric and glacial acetic acids. A few wide- mouthed stoppered bottles will he required for otiier bottles. Crystals of nitrate of silver_, pyrogallic acid_, &c.;, and ordinary stoppered bottles^ of various sizes^ for different solutions. STILL. Much distilled water is required in the process, especially when large sizes are undertaken. In cities, earboys of it can be readily purchased, and the time of the photographer not intruded upon by its preparation. When operating away from home a small still gives the means of being certain To prepare distilled water. Fig. 35. of a supply. When the body is filled with water it is corked up, and put on a fire ; the worm- tub” requires to be kept full of cold water, which, as it becomes warm, is drawn off, and fresh added through the funnel. Eain water can seldom be PRINTING FRAMES. 93 obtained sufficiently pure^ being contaminated by appaeatus. contact witli oxidised lead gutters_, &c. Clean ice melted gives very pure water, and may serve on an emergency. SPIRIT LAMP When operating away from home is necessary. If the atmosphere is damp it is advantageously applied for a few seconds to the back of the glass plate, just before laying the film; the moisture will be Used in lay- . . ing the film, seen to leave the surface. When the negative is finished it afiPords the means of heating the plate previously to varnishing it, thus putting it in and vamish- in®*# safety before returning home. PRINTING FRAMES Are used to place the negative, with the excited paper superposed, in the light. They should be purchased with jointed backs, to allow the pro- gress of the action to be inspected. Note well that the thick front glass does not fit so tightly that it cannot be easily pushed out. This is a fertile source of broken negatives. These frames are exposed to great and sudden variations of temperature; and if the thick plate"' is jammed andiiabiuty in tight, as is often the case, it is sure to be de- stroyed, and most probably the negative wiU share its fate. 94 REQUISITE APPARATUS. EXCITING TEAY. Apparatus. No substance OP surfacG equals glass for eon- of glass tainiug tbe sixty-g-rain solution of nitrate of silver necessary. _ ° used in exciting tbe paper for photographic ♦print- ing. Gutta percha communicates a very distinct Fig. 36. brown tinge to the paper^ indelible by the sub- oiheisde. sequent processes. The glaze of Wedgewood ware tenorating. withstand the action of the solution^ which traverses its structure^ and the surfaces of both are deficient in evenness. The only mode of ob- taining glass trays for this purpose is to construct them of plate glass^ as it is not possible to procure them of anj' size in one piece. The method given in the cut has the advantage of giving support^ by the wooden casing, to the glass plates, thus keep- ing them in their form and preventing risk of external injury. It is necessary that the casing Wooden should be made of well-seasoned mahogany, other- casing. wise the very means taken to protect the glass would, by the shrinking of the wood, destroy it. If FOCUSING CLOTH. 95 a white millboard or paper is put on the wood by the ApgARATrs, maker^ previous to the bottom glass being placed^ it wdll enable the operator to detect with more facility any impurities which may be in the solu- tion or on the surface of the glass. FOCUSING CLOTH, &c. A piece of the thickest black cloth procurable ; Quality re^ commended. held up to the light it should not allow any to be seen ; it will be found to adapt itself better to the movements of the operator than the India rubber cloth, sometimes recommended for this purpose, serve other purposes. which, however, should always be taken as well for outdoor work, as it saves the camera, &c., from rain. Straps or India rubber bands are useful, and some squares of yellow and black calico, single and double, are very handy. Focusing Eye Piece. — Is of great utility, it imjjortance enables the operator to examine the definition of cusing. the picture on the ground glass screen, and to determine the exact focus with greater accuracy than is possible with the unassisted eye. Linen Cloths, for cleaning the glasses, are The qualities ° requii'ed. better of old table-cloths, napkins, &c., than of new material. Some pairs of large white cotton gloves for the assistant who polishes the glasses. Some old silk handkerchiefs and some wash-lea- thers j the whole of the above must be rendered 96 REQUISITE APPARATUS. Apparatus, and preserved chemically clean^ as described article Glasses.^^ Two or three very soft wash -leathers^ the dust well beaten out of them, not washed^ to clean the lenses. TEST AND EILTEEING PAPEES. Use of test Litmus paper is required for testing the nitrate bath, toning bath, &c. : filtering paper of the best quality for the nitrate bath and solutions, and abundance of new blotting paper for the manipu- lations. Note, that the foregoing is a list of complete apparatus proper for executing works of impor- tance; it is easy to suppress some items, and diminish size in others, should the nature of the study undertaken not necessitate them. PAET III. MANIPULATIONS. PREPARING THE CAMERA. Before placing tlie film in tlie camera, it is manipula. ^ ° TIONS. necessary that the latter should be in every way prepared to receive it, and all precautions taken which may insure a successful issue. The lens must he perfectly polished with its Precautions appropriate leathers~the inside of the camera carefully dusted — the exact distance from the subject fixed, and the size the object or objects appear, and the 'position they occupy in the field found satisfactory — the height and inclination of the camera decided upon — and the necessity, or otherwise, of using the swing back and moveable fronts studied — two or three diameters of dia- their nature, phragm must be tried, and their efiects on light and focus observed. These preliminaries having been attended to, we next proceed — 7 98 MANIPULATIONS. TO LAY THE FILM. manipula- The glass plate^ having been scrnpnlonsly cleaned ^ according to the directions given^ is put on the pneumatic holder, and the trigger being drawn down into the catch, the glass is fixed in its place : its surface must be well polished with an old silk handkerchief at the last moment that the operator is ready to lay the film. Observe that all doors and windows are shut ; the ether is sufficiently Currents of rapid in evaporation, and draughts disturb the air, air injurious. . i i • *7 raise and bring in dust. If there is much humidity in the atmosphere, it is well to hold the surface to be operated upon, for a. few seconds only, before the fire or over a spirit lamp ; the moisture which had condensed on the glass will be seen to leave it. The stopper and neck of the collodion bottle being carefully wiped from the horny crusts of Mode of hold- former pourings, take the holder firmly in the ing the plate, /.-.t • i i 71*1 left hand, raise the plate to the height ot the chin, that the eye may readily appreciate the flow of the collodion, hold it perfectly level, keep it at arm^s length, and especially refrain from talking and breathing over it, as the moisture of the breath becoming condensed on the surface of the glass, would seriously deteriorate the film. Now, lowering the mouth of the bottle down LAYING THE FILM. * 99 within an inch or so of the glass to avoid bubbles, splutterings, 8ce., — to do which the bottle must not be more than two thirds full — pour firmly and steadily in an even stream— without pause or jerks — until there is sufficient collodion to cover the size of glass that is being operated upon. Prac- tice will soon determine the quantity necessary, which is about three fifths of the entire surfaee ; the student should hasten to aequire this know- ledge, as if too little is poured on the glass, loops and streams will be formed, eneircling bare glass, and the latter then beeomes most difficult to cover evenly. — If too much is poured out, collodion will probably be wasted by running over, in get- ting the superfluous quantity back into the bottle. A few trials will firmness j neatness, and quick- ness to the manipulator. — The best way in cover- ing a plate is that in which the collodion has only to travel once over the same surface, and not, as it were, form a second strata, by returning over part of the half set first, to the pouring ofP corner. To accomplish this is most simple j in pour- ing it is easy to give such a slight motion as shall cause the pool of collodion to assume an oval instead of a round form. Pig. 37 Manipula- tions. and pouring the collodion. Quantity ne- cessary. Mode of co- vering. A 100 MANIPULATIONS Mawipula TIONS. illustrated. Rocking tha plate. 38. ^ having sufficient^ stop pouring — a depression of the corner a will bring the collodion to the edge^ in the form shown (fig. 38) ; on lowering the corner b the collodion fiows to it^ and there is^ as shown in fig. 39^ now only one motion^ of a slightly c D rotary kind^ which sends it at once both to complete the corner Cy and to which^ being inserted in the month of fhe bottle_, the surplus is poured off gently_, not rais~ angle of twenty-five ing the degrees^ above an as if held up vertically, or at a greater angle, reaminess and strise will form which cannot be got rid of; rock it gently from c to a, to antago- nize the current from b to n, and thereby render it even; if this is done violently in jerks the film EXCITING THE FILM. 101 will be cracked. As soon as it has done runnings manipula- TIONS.> in hot weather — or after it has stood a few seconds horizontally in cold : take it from the holder^ Afterwards ^ ^ ' placed hon- place it on the dipper, still keeping it nearly horizontal in position. EXCITING THE FILM. Now, observing that all white light is strictly excluded, advance to the mouth of the bath, and with one steady even movement lower it to the bottom; should any pause take place there will subsequently appear straight lines of stain, from side to side, across the negative; if the film is dipped too soon, in cold damp weather, reticu- lated fissures in the film will probably appear ; if kept too long, before placed in the bath, blank patches of insensitiveness will result ; besides the qualities of temperature and atmosphere, the na- ture of the sample of collodion must be taken into consideration: a thick viscid collodion will require twice as long before dipping as a thin subtile one, and if subjected to precisely the same treatment both would be spoiled. The time re- Time re- quired. quisite to leave the film in the bath varies with the temperature, requiring much longer in cold Dipping into tlie oatL 302 MANIPULATION^. manipula- than in hot weather^ and the plate may he left TIONS. longer in a hath which has been some time in use than in an entirely new one — two to three Varies with minutcs is a mean time. After it has been a temperature. minute or so in the bath_, hut not before, it should be gently raised and lowered_, some five or six times_, to even the action of the iodide_, and then left to complete the time proposed. Now raise it gently, if all oily streaks have disappeared, and the surface appears even, it is ready; hold it a moment at the mouth of the bath to drain, then put it upright on a strip of clean double-blotting- paper, leaning the back against a bottle ; when it has stood from five to forty seconds — again by Plate drained, temperature and area of surface — to drain, place it in the back or slide, at the four angles of which small pieces of clean blotting paper should have been placed to receive any moisture, and covering the back of the glass with blotting paper, close Ready for the the slidc and get it to the camera and in action as camera. ^.^pidly as possiblc, siucc delay has the effect of diminishing its sensitiveness by drying the film. 103 TO EXPOSE THE FILM. In taking tlie slide or back from the operating manipula- ® X O TIONS. room^ or returning from the camera^ be careful not to reverse or alter its position from the vertical, in Position of ^ \ the slide. which it stood during exposure ; some bath drain- ings will be sure to accumulate at the bottom, which, contaminated by contact with the slide, would, if it were not held in the same direction, run back over the film and stain it. If operating from the life, focus at the last moment before put- ting the slide into the camera. Now remove the ground glass, replace it with Precautions to be ob- the collodion back, cover the top of the latter, served, and keep it scrupulously covered with the focus- ing cloth, otherwise light will get to the film, and uncap the lens without shaking the camera. The time of exposure expired, cap the lens, ob- serve that you lower the sliding shutter very gently y if done otherwise the bath drainings at the bottom will be splashed up the film, and the negative spoiled. 104 MANIPULATIONS. Manipula- tions. Its great im- portance. Fixed rules impossible. The most fa- Torable con- ditions. TIME OF EXPOSURE. In the whole range of photographic manipula- tions the sum of which goes to make up the perfect picture, there is not one of more im- portance than the correct time of exposure in the camera. No fixed data can be given for duration of exposure, since occasionally the subtilty of the changes between very short intervals of time may render one negative intense, and the one imme- diately following it weak and defective, with the same treatment. Still, by practice, a sort of instinct grows on the photographer, which often leads him to alter on the moment a predetermined thirty seconds into twenty, or vice versdj after the film is uncovered, according as the quality of the light may have impressed him during the operation. The only general rules to assist our estimate of the actinic power are the following, which expe- rience has shown to be the conditions most favorable to the production of the photographic image; namely, the time of day, as near the meridian as may be; the purity and freedom from vapours of the atmosphere immediately on the earth^s surface; which, to estimate it pro- TIME OF EXPOSURE. 105 perly, requires the command of an extended manipul>- horizon. The time of year— spring and early ■ summer^ with a moderate temperature — sixty to Temperature, seventy degrees Fahrenheit — not that it is the writer’s opinion that the action of a low tempera- ture is entirely deteriorating to the exposure in the camera ; as during clear frosty weather^ un- accompanied by vapours, he has made satisfactory negatives — failure seems more to be caused by the effect of cold upon the chemical agents used Effect of cold, in the process, which impedes or arrests their sensitiveness. When this has been carefully guarded against in clear weather, in December and January good actinic quality has been expe- rienced. The temperature of the glass house and dark room at such times must be raised, by fires and hot-water pipes, to sixty degrees Fahrenheit, t 1 )c chemi- cals, &c., be- and in the temperature the bath, the developer, ingprotected. the collodion and the glasses, which are to receive the film, must have been kept a sufficient period to acquire the same heat; likewise the camera and lenses ; for should they have been brought in from a lower temperature, the vapour from the collodion film would, during the time it was un- covered, be condensed on the lens, and interfere with its action. Now, although cold weather does not, with these precautions, prevent good and vigorous negatives from being executed ; extreme heat has Effect of 106 MANIPULATIONS. Manipula- tions. Other influ- ences. Negatives under-ex- posed. a very damaging effect^ against which no efforts of the photographer will avail; its influence is not only felt in the exposure, hut by the chemi- cals of which the nitrate hath and collodion are the two most deteriorated in their qualities ; this will he found treated of under the head Nitrate Bath, and Collodion. The writer has observed that the action distinctly improves after rain has fallen, whether during the bright intervals between smart showers, or the morning after a more continuous fall; occasionally, even during heavy rain, the action has not been impeded. But the process is retarded, and the action is often entirely deficient in hot sultry weather, in which the atmosphere is surcharged with electri- city ; a thunder-storm will at once restore excel- lent photogenic qualities. Elevation of ground is decidedly favorable. Photographers in general more often commit the fault of under than over exposing their nega- tives; now it would he desirable to reverse the error, and, if we cannot hit the precise moment of time, that they should, of the two, be over-ex- posed, since in the former case the result is abso- lutely valueless ; in the latter, we have two favor- able chances ; one, that if skilfully manipulated, it is in our power suddenly to arrest the progress of the development at a point which shall retain most of the qualities necessary to its printing TO DEVELOPE THE IMAGE. 107 successfully^ the otlier^ that some subjects do not Manipula- T . P . TIONS. lose by a slight over-exposure , it oiten ^ives ~ atmosphere and sunny effect in landscapes^ and with some arrangement, delicacy to female por- traiture. Indeed, it is more than doubtful whether the greater portion of the most successful results its results, which we see are not more consequent upon this balance of exposure and development, than to tlie exact timing, to a second or two of exposure. Not that it is possible to produce a fine picture if the expositre has gone beyond a certain limit; the nearer we hit the correct time, the better the Correct, result, but of the two errors over-exposure is the less fatal. TO DEVELOPE THE IMAGE. The slide having been brought back to the dark room from the camera, we now proceed to develope the picture. The strength of the strenjrth of solution to be used must depend upon the tem- peratmre ; when that is high, as in summer, it is advisable to reduce the developer by adding two parts of distilled water to one part of the three grain pyrogallic solution; in medium weather. Dependent on thermometer 60° to 70°, one third water to two thirds of solution, — and when the temperature is below 60°, using the full strength. Take the glass 108 MANIPULATIONS. manipula- carefully from the slide by the edges, avoiding ^ touching the film, place it on the developing stand ; now take one of the developing glasses, in which, just before going out to the camera, the solution should have been prepared — a larger one, half full, depresses and spreads better than a small Mode of ap. One full — quickly and skilfully pour the developer, plication. • n i as much as possible at one motion, all over the film, avoiding especially pouring it in one place — now put down the empty developing-glass, take the plate by the two nearest corners, and rock the solution rapidly hui gently backwards and forwards, — if necessary, from portions of the surface re- maining uncovered, and not flowing readily. Its action de- blowing it at the same time. At first, particularly scribed. ^ ^ ... with the diluted solution, it will have a great tendency to draw together in uneven greasy patches, but it must not be allowed to rest, other- wise there will infallibly result stains and ble- mishes, — after a short interval it will lie smoothly on the film. If properly exposed, in medium temperature. Appearance the picture should begin to appear in ten to ot the image. seconds j at this point the experienced operator knows, at a glance, the quality of the Treatment if negative. Should the image dash out immedi- i»fl«-exposed. developer is applied, it has been over- exposed— it may be irrecoverably so; in which case a general decomposition immediately ensues. TO DEVELOPE THE IMAGE. 109 If it has been less, be quick to stop tbe action manipula- T 1 TT/.1 TIONS. with water, which must always be at hand tor the " purpose. Over-exposed negatives, when held up to the light, show a want of vigour in the deposit on the high lights, and a tendency, more or less, to general indistinctness from fogging. If it is Fogging, desirable to increase the intensity on the high lights, and to clear the darks, proceed as follows : Apply the saturated hypo fixing solution, when the yellow iodine is gone, wash well with plain water, and after rinse with distilled water; now placing the negative again on the stand, apply fresh developer, of fuU strength, with some drops of bath solution decomposed in it ; the result will, of coprse, not be so good as if correctly timed, but generally this expedient will improve a weak over-exposed plate; wash, apply the hypo sol., and steep in water. If the exposure has been when under- . . exposed. faulty, by being too short, the image will appear very slowly, the more so as the light was in- efficient or the exposure defective; the white lines first alone, after the high light on the face and hands appear ; the parts in shadow and dark draperies being entirely neglected, are the signs of such a plate, which is totally worthless, except to serve as a guide for rearranging any parts of the composition which may appear defective, and to regulate the exposure of the next film. If the exposure has been successful the white 110 MANIPULATIONS. Manipula- tions. 'W'lien suc- cessful. and light draperies^ the head^ hands^ &c._, will be well supported by other forms_, and even in the dark local colonrs_, as of dress^ hair_, &c.^ drawing will appear ; the development should be stopped when all but the very deepest shadows^ the pupils of the eyes_, &c., are filmed over^ the latter should remain near bare glass ; if taken precisely at this point the picture will have spirit^ rotundity, and variety of tones, from the most delicate tints of shadow on white to small portions of vigorous and spirited black, which will not only give the neces- sary scale, but will likewise produce form and give atmosphere to the subject. It sometimes happens by certain combinations of temperature, light, or both, that although the exposure may be correct, and the gradations are satisfactory in the picture, the deposit is not quite sufficient in intensity ; in which case a few drops of bath solution added to the developer will improve the negative; but it is necessary to remember, should the appearances on the glass be almost right, that if this operation is injudiciously performed the half tints in the Adding bath flesh of a fine head may be rendered opaque and solution liable ^ it t*j r»*T to deteriorate spoilcd, that tfic dccomposcd nitrate ot Sliver has the picture. decidedly a tendency to attach itself more pro rata to the high lights than to the parts which have been less acted upon in the camera, and that if such a solution is left on the subject more than a few seconds a general muddiness, irrespec- Deficient in intensity. TO DEVELOPE THE IMAGE. Ill tive of all forins_, makes its appearance^ and tlie manipula- TIONS. brilliancy of tbe subject is gone. If tbe subiect is larqe. it is well to commence Developing ^ large sizes. with the dilute solution, as being less liable to cause stains, from its slower action and giving more time to cover the film evenly. When the greasiness before mentioned has disappeared, a stronger developer may be applied with less risk. Should there be in the composition strong opposition of local colours over which the opera- tor had no control, and which would be likely to come out spotty, as, say, a white cottage in a landscape, or very light or dark draperies in a figure subject, an expedient maybe resorted to useful exp«- which, if skilfully manipulated, corrects the exaggeration of such parts. The developer must be used of one- grain strength, and must be moved until it lies quite evenly ; two chemically clean glass syringes must have been filled, one with distilled water, the other with three-grain solution; now a few drops of these into the floating one-grain solution respectively, over the too white or too dark parts, will retard the one and advance the other. Generally it is better, if the subject is not too Better to d.6vdop€ large, to develope smartly, there is decidedly more smartly, spirit in the result than there would be by mani- pulating slowly with a weak developer; but, of 112 MANIPULATIONS. manxptjla- course^ the operator must then he more watchful TIONS, . , , . . " to prevent stains_, by keeping the plate in motion. Too small or It is ob] cctionablc to use too small a quantity too large a u j quantity Ob- dcvcloper on a plate, the chances of stains are jectionable. ^ sr ^ infinitely increased. It is also not desirable to use so large a quantity that it runs off the plate, as then it carries with it the silver which was in the film, and which was necessary to form the image. APPEARANCES OE THE IMAGE WHEN DEVELOPED. The developed picture, viewed by transmitted light, differs in its appearance, even when pos- sessing equally favorable printing qualities. There Varieties of Variations of colour in the image, and of real colour, apparent intensity of deposit, which are caused by the changes and relations towards each other of the bath and collodion, as the acidity or neu- trality of either the one or the other predomi- nates. Likewise, independently of duration of exposure, varieties of appearance are caused by changes in the quality of the light ; often in the same locality, on the same day, with the identical chemicals, negatives differing in translucence or and opacity j Opacity and colour ^ are produced; but which may. IMAGE WHEN DEVELOPED. 113 Dotwitlistanding tlieir varied cliaracter_, all have manipui,/. equally favorable properties. The negatives taken ^ with a bath prepared with acetate and carbonate of silver, are especially distinguished by a great range in their colours, from a pale inky black, through dark blue-blacks, browns, and marones, to deep reds. The best printing qualities for a negative to The best qua- lities possess are the following : the high lights in the picture, that is to say, the most intense portion of the deposit, should allow the flame of a candle to be just seen through when held behind them ; if of too great an opacity to admit its being per- ceived at all, the resulting positives will probably be chalky and bare in the lights, and deficient in half tones. There should be a general deposit of in & negative silver, with considerable variations of intensity, over the whole surface, with the exception of the most vigorous darks, and in them it should ap- proach very nearly to the bare glass, but only in small portions, if in large masses it would denote under-exposure. Held up to the light, colour by their colour should be of a warm inky brown ; li^u when the plate is held horizontally over a dark ground, and viewed by difiused light, the ap- pearance which especially distinguishes the deposit on the film in all negatives of the highest capa- by diifused. bilities is an earthy drab colour. Such negatives are sure to print well, all the objects represented 8 114 MANIPULATIONS. Manipula- tions. Posseases every grada- tion ot tone. Compared with imper- fect. “ Assisted ” development. Defective, and why. by them will be rotund in appearance^ because their forms are thoroughly delineated by delicate half tints^ and the extremes of light and dark^ with all the intermediate toyies, will be well expressed. Their effect will be bright and spirited, equally removed from the vapid monotony of over-exposed negatives, which are deficient alike in both whites and blacks, and from the crude and misshapen forms of the under-exposed, which fail, because wanting the softening beauty and drawing given by middle tints. When the negative has been assisted, in an inefficient exposure, by the addition of drops of nitrate bath to the developer, the peculiar drab colour of high actinic quality will not appear when examined by diffused light; in its place, darker tones and more opaque deposit of a blue or black character are seen. They are less satis- factory, being deficient in the truth and delicacy of gradation possessed by the former, and are apt to be very deceptive when printed ; dark and vigo- rous looking negatives occasionally allowing the light to permeate through their texture, whereas the most translucent of these impressed under favorable actinic conditions have a great power of resisting it, although their weak looking, light brown deposit, would appear ill adapted to do so. 115 FIXING THE IMAGE. Having been tboroughly washed from the solu» manipula- tion^ the developed plate must now be fixed. The most convenient mode of doing so. for small convenient and moderate sizes_, is to have a gutta percha bath^ with glass dipper^ containing the hypo fixing solution ; the plate is immersed in it pre- cisely as it was in the nitrate bath. After the lapse of a short period it is raised^ and if any of the yellow iodide remains undissolved it is re- iodide must • 71 1^® entirely turned to the bath. It it appears entirely cleared^ removed, it is taken off the dipper and laid on the film upwards to steep in water. Common jelly-pots make excellent rests to stand the plates upon in a sink. The quantity of water depends on the size The film weu of the plate. A pint for the smallest size^ in four intervals of a quarter of an hour each^ will suffice ; for the larger^ two or three quarts in the same period. If they are inefficiently washed the hypo will not be dissolved out^ and remaining on the film_, will make its reappearance in crystals, to the certain destruction of the picture. If the sizes Another are large, or it is not wished to have a bath ex- fixing, pressly for the fixing solution, the best mode of applying it is as follows : take a large W edge- wood tray, stand in it four jelly-pots bottom 116 MANIPULATIONS. Manipula- tions. Hypo solu- tion removed Precautions, upwards^ place the negative on them^ and pour the hypo on it from a jug; the solution is not wasted_, being returnable from the tray. In adopting this mode_, it is proper that the jug used should have a perforated strainer in its spout^ which will intercept any crystals of hypo frag- ments of film^ or other impurities^ which would drop on and mark the plate. VAHNISHING THE PICTURE. The negative must have been sufficiently washed with clear water^ so as to have removed every trace of the hypo fixing solution from the film ; at the same time it is not advisable to allow water to remain too long, as it then seems to weaken the film, and cause reticulation. In the summer weather beware of the flies, who appear to have a great propensity to settle upon and mark the film, and of the dust, which is likewise injurious. Let the subject be placed upright, facing the wall, on a slip of clean blotting-paper to absorb moisture ; see that the varnish bottle is clean in the mouth, a twelve-ounce tail collodion bottle makes the best varnish bottle, as the weight of the column of varnish tends to sink any impurities to the bottom, and the upper and clearer portion only will he VARNISHING THE PICTURE. 117 used. Now hold the negative with the hack manipula- « T . . TIONS. towards a ffood fire, or if from home over a spirit- ^ ^ J- ]\ep:ative lamp^ not too near, however, and move it gently, so that it may he evenly heated. This operation, particularly in cold weather, must he performed carefully, or the glass may fly. Having heated it so that the hand can just he home comfortably on the hack of it, take hold of the corner with the fingers and thumb of the left hand, and pour the varnish on the centre of the plate, send it from Mode of ap- corner to corner, precisely as the collodion film vSsh is laid, and pour off into the bottle. It should not be held vertically to drain, which would cause ridges and inequalities on its surface, hut must he treated precisely as directed for laying the col- lodion film : when nearly set, it is well to stand it on a slip of clean blotting-paper, which will absorb any varnish, which would form a ridge or fringe^ ^ at the bottom of the plate, and be detrimental when printing. If the glass is over-heated, the results are that Effects of it will possibly fly when the cold stream of var- nish is poured on it, or it will seeth in bubbles on the surface ; and such a negative, when dry, is sure to be destroyed by the varnish cracking and rising up in scales, bringing the collodion film away from the glass with it. If the plate has been and insuffi- insufficiently heated, the varnish will chill in drying, and its opacity will seriously interfere with 118 MANIPULATIONS. Manipula- tions. Vernis SoeIm6e. Amber var- nish. Treatment of damaged surface. the successful printing of the subject. The best varnish to use for this purpose is a spirit-varnish^ manufactured in Paris^ it is the ‘'Vernis Soehnee/ and is retailed in London by most of the dealers in photographic apparatus. The amber and chloroform varnish cannot he recommended^ its powers of adhesion to the plate are too weak; hut the writer has known it to stick to the fingers^ with part of the subject from the margin of the plate attached_, long after care- fully finished ; for out of door work it may have advantages^, when a picture is required to he im- mediately varnished,, as the glass does not require to he heated for its application. If a negative has been printed in the direct sun-lighL and has had its varnished surface injured; by placing it on the developing stands carefully levelled^ and allowing chloroform to remain upon it a few minutes^ the injured surface will be dis- solved^ and it can be revarnished when dry ; this applies equally to both the above varnishes. Observe that a few hours should be allowed to elapse before printing from the newly varnished negative^ or it may probably suffer by adhesion to the paper. 119 DEFECTS, THEIR CAUSES AND REMEDIES. Having described favorable appearances in manipulx- -1 T • o -T IT -n TIONS. the deposit oi silver on the plate, we will now proceed to examine the imperfections and show Defects ^ their nature and origin, and this portion of his importance y* 1 1 ^ analyzing, experience is oi as much or more value to the operator as any ; for in a process consisting of a great variety of manipulations, on the complete success of EACH of which the perfection of the resulting picture is dependent, it becomes of great importance to possess the power of distinctly referring any failures to their exact origin, and and tracing tx> their source. thus being enabled to apply the necessary cure. Otherwise, the student would have the mortifica- tion of seeing plate after plate appear on develop- ment with the same blemishes, to which, having been unable to trace their source, he would be incapable of applying a remedy. It is well, therefore, to acquire the habit of never passing an imperfection, and not resting satisfied until in all the various processes the one causing it has been discovered. The first defect we will notice is of frequent recurrence ; it is a general obliteration of the opaque mm. forms of the subject in an opaque film, which 120 MANIPULATIONS. POGGINO. “ Fogging,” its causes. Over-strong developer. Nitrate batli alkaline ? Remedy if found so. prevents them from being clearly distinguished^ in whatever direction they may he viewed. This is termed fogging/^ and is caused in a variety of ways. It may result from the unskilful use of the developer itself ; if it is of too great strength in warm weather^ when it should have been reduced in power by the addition of distilled water^ fog- ging will ensue; or^ at a more moderate tem- perature,, prolonging the time of development beyond a certain limits will cause the same ble- mish. If weakening the solution in the one case,, and shortening the development in the other^ does not remedy the evil, the nitrate bath must be tested for alkalinity with reddened litmus paper."^ If its condition is found satisfactory, i. c., fleutral or just acid, which will be seen by its allowing the reddened litmus paper to retain its colour, the fault is not there. If it restores it to its former tone it is alkaline, and a drop or two at a time of acetic acid must be added ; testing between each change with the blue paper, so as not to exceed the quantity necessary, which will be when the paper is tinged with red. Stir witli a glass rod * Litmus paper, when used to test for alkalinity, is first red- dened. This is best done by taking out the stopper of an acetic acid bottle, and holding a strip of the paper in the fumes inside ; it will immediately change from blue to red. Actual contact pro- duces a less sensitive test paper, its texture being completely saturated with the powerful acid. DEFECTS^ CAUSES AND REMEDIES. 121 during the time^ that the drops of acid may he foggi^ equally distributed throughout the bath solution_, and their action not confined to the mere surface. When there is only a very slight tendency to very sUgU] fogging. fogj it is better not to touch or alter the bath j by using a more highly coloured sample of collodion perfect clearness of definition will be restored to the film^ whilst at the same time every plate of such quality of collodion that is dipped will tend gradually to displace^ more and more^ the small tendency to alkalinity existing in the bath. Indeed_, with such a combination and balance of properties^ an acid collodion and a neutral bathj most excellent qualities are produced in the Excellent . -- . combination. picture; the bath_, on the one hand, possessing the power to accelerate the action and delineate the difficult colours or obscure radiations from the subject ; whilst its inclination to fog is bridled by the acid state of the collodion, which keeps the general definition of the plate and its darks and half-darks bright and clear. Should the bath, when tested, be found in good condition, the fault may be with the acetic acid ; Acetic acid deficient in if it is deficient in strength it will not moderate strength, sufficiently the action of the pyrogallic in the developer, on adding about a sixth to one quarter more than its original proportion to the solution clear plates will be obtained. When not arising from these sources, fogging may be caused by 122 MANIPULATIONS. Fogging. Uilfiised light, and reflexions. An old bath. Over-expo- sure, Means of ascertaining Insensitive film. diffused light having acted upon the film either in the operating room^ the slide, or the camera, or from the reflexion of light from bright surfaces in the studio, or portions of sky acting directly on the lens. An old hath has occasionally a tendency to fog, from the accumulation of organic matter and presence of oxide and nitrite of silver; the best remedy in this case is to replace it by an entirely fresh one. Lastly, and more frequently than any of the preceding causes, over-exposure at large apertures of double lenses is a fertile source of this imper- fection. One general line of demarcation exists in fogged plates, which materially assists the operator in discovering the origin of the evil ; it is that when fogging proceeds from impurity in the chemicals it is on the surface, and is remov- able by gentle friction with the finger. If it has been produced by over-exposure or diflused light it is in the body of the film, as much as any por- tion of the subject itself, and is incapable of removal. The next blemish we will notice, is the direct opposite to the fogged appearance on the plate : it is the insensitiveness evidenced by the too great quantity of hare glass seen on the plate, this is caused probably by acidity of the bath, which must be tested for it ; if there, its presence will be DEFECTS_, CAUSES AND REMEDIES. 123 denoted by the greater or less degree of intensity insensittvk of the red colour which it imparts to the litmus Bath tested for acidity. paper^ and according to the proportion^ so must the quantity of the alkali_, applied to rectify it^ be regulated. Some operators recommend am- monia for this purpose ; the writer advises drops of a solution of carbonate of soda_, dissolved in distilled water^ to be used in preference^ having found it in practice give much better results. It must be applied very gradually, and the test- paper and stirring-rod used as mentioned before. If on testing the bath its acidity is not con- siderable, and the operator has been working it with a rather highly coloured collodion, instead of Over-iodized collodiou. meddling with the bath the balance before men- tioned can now be restored in the contrary direc- tion — namely, by using the most neutral sample of collodion at hand, which will be found as efficacious in restoring sensitiveness, and giving delineation of forms in the bare portions of glass, as the acid collodion was in clearing the obscured plate. If the bath is not in fault, the exposure in the too short an camera has probably been of too limited duration, or the diameter of aperture less than the quality of light would bear ; increasing the time of the first, or enlarging the other, will entirely alter the character of the succeeding plate. Keaminess or wavy marks are most likely to waviness. 124 MANIPULATIONS. Reticula- tion. Collodion too viscous. Consequen- ces. Must be di- luted, and how. occur iu thick viscous samples of collodion^ which are diffieult to get off the glass with suffieient eelerity ; in hot weather all collodions will be apt to have this defeet^ owing to rapid evaporation of the ether in manipulating. This unevenness is most offensive in large flat tints_, haekgrounds_, &e.^, with whose perfeet ap- pearanee it of eourse greatly interferes^ but it is highly detrimental and objeetionable in all parts of a pieture^ for as the thickness of the collodion film is doubled in such parts_, no treatment which will apply to them will be sueeessful for the rest^ and vice versa. If the film be detained until they are set, the other parts will be dry and insensitive ; if they are immersed when the rest of the film is ready^ from not being set they will be still unset^ and being soft the other portions of the film will drag them^ and they will be full of reticulations, whieh eonditions oeeurring aeross features_, &c.^ are very destruetive to the pieture. In warm weather, especially, the state of the eollo- dion must be carefully watched, and as it thickens by evaporation, newly washed ether and alcohol absolute must be added, in the proportion of two DEFECTS^ CAUSES AND UEMEDIES, 125 parts of the former to one of the latter^ until the necessary fluidity is attained. Small white circles, as given in the cut, appear in the subject. This blemish is caused by the operator elevating the mouth of the col- lodion bottle too far from the glass in lay- ing the film 3 the ac- tion established in the liquid, by the minute bubbles created, remains after they may have dispersed, and their traces reappear in the finished work in the manner shown. If care is taken to depress the mouth of the bottle suf- Not to pour ficiently, before beginning to pour the collodion, these marks will not occur. Peculiar serrated marks are caused by a greasi- serrated ness or scum on the surface of the bath, which attaching itself to the film, slides down it when put to drain. This defect dis- appears after dipping two or three plates, showing that they have exhausted the impurity and cleansed the surface g^^sy sram. Fig. 41. 126 MANIPULATIONS. Spots. Spots of tran- sparency, due to nitric acid and Tripoli, or action of nitrate of silver. Spots of opa- city, for succeeding ones. This blemish is entirely consequent on the contact of gutta percha with the bath solution; all other precautions being taken to avoid the presence of organic matter^ it is unknown in a glass bath. Spots are of two kinds ; those of defective action^ leaving bare glass^ and printing black_, are caused in the following manner. Tripoli and nitric acid, recommended sometimes for use in cleaning the glasses^, adhere most tena- ciously to their edges^, and if present will^ when the plate is dipped in the bath^ be dispersed by the solution^ though it was intractable to water^ and settling on it, and on succeeding films, causes spots of bare glass to appear. Pre- pare them as directed, article Glasses,^^ and carefully filter the bath. A film that has been kept too long in a new bath, or that has been delayed before ex- posed in the camera, will thus become dry, and the collodion being acted upon by the nitrate of silver, numerous minute spots are eaten into its structure. The contrary appearance — that is, spots of opacity on the plate, printing white — is produced Fig. 43. DEFECTS^ CAUSES AND REMEDIES. 127 by dust settling on the film in certain stages of CoMKTg. adhesiveness of the latter^ and not forming from dust, Comets/^ but spots^ by minute centres of in- creased action. By the film being laid from a highly coloured sample of collodion^ and exeited in an old bath which has become over-iodized ; lastly, and most frequently, by too prolonged de- velopment of an under-exposed plate, and using excess of drops of bath solution in the developer, “Drops” in the effect of which is to cover the surfaee with minute specks of concentrated deposit of silver. Photographic ^^Comets^^ are defeets which bear » comets,” a remarkable resemblance to the forms of their prototypes ; they are caused by particles of dust caused by dust. in the atmosphere of the developing room, which, descending on the wet film, reappear in the picture in the shape of spots, comets, &c., by the action for which they serve as nuclei ; when they arise from this souree, the tails, &c., stream from them Fig. 45. 128 MANIPULATIONS. COMKTS. Remedy. Resulting from COHO'- dion. Differ in their form. Lines cross- ing tlie plute. in a vertical direction as they lie on the sur- face of the tilm^ and are caused by action in the bath liquid^ retained by them_, bowing downwards Greater care in clearing away dust, &c._, will prevent their being seen on the plate. They will likewise arise from an inferior quality of col- lodion; from carelessness^ with a good sample_, in not decanting the upper part of it from a large stock bottle into a smaller^ thus leaving all impu- rities of former manipulations behind ; by using the collodion immediately after iodizing; or from not wipings with sufficient care, the necks of the bottles from dried fragments of collodion or dust, or from any fine, &c., off the glass-cloths, adhering to the surface of the plate. When they are in the collodion itself may be known by the tail-like appendages, &c., tak- ing a curved form of direction, consequent upon the rotatory mo- tion imparted to the liquid in laying the film; whereas those de- pendent on the action of substances merely resting on the surface of the film, have direct vertical lines of drainage action. Straight lines, of varied intensity, crossing the plate from side to side, are caused by any pause F)g. 46. DEFECTS^ CAUSES AND REMEDIES. 129 or hesitating movement with which the dipping of the film into the nitrate hath may have been accompanied. As has been mentioned^ the action should be firm^ prompt^ and consecutive. Marks often appear like small beards of light following the forms of the high lights of the sub- ject^ and streaming downwards from them in the direction in which the film stood when exposed in the camera. This de- fect is caused by the plate not having been sufficiently drained before exposure ; the action is caused thus : The rays of light which delineated the fingers, linen, &c., in the image, were diverged and reflected by the de- scending liquid, and possessed, in the immediate vicinity of the high lights, sufficient power to impress an action. Eemedy — to obtain a clearer outline, drain the plate more before putting it into the slide. The marks do not attach themselves to the forms in the pic- ture, but are seen as Fig. 48. Fig. 47. Stains. caused in dipping. Defective drainage marked in the camera. In dark room. 9 130 MANIPULATIONS. Statns. Streaks, how caused. Diffused light. Impurities iu bath. Deficient illu- mination a parallel streakiness of various intensity and width, across the picture. These appearances may arise from three causes^ and the following tests will enable the operator at once to decide to which he should refer them. The subject was taken in the camera_, of landscape form^ hut the marks appear in the contrary sense. The defect was in Ihe dark room ; diffused light_, some crevice^ or insufficient yellow blindage^ were the cause — that is to say, if they are incapable of removal when the film is gently rubbed either with cotton wool or the finger. Marks similar in appearance to those just described, hut appearing in the sense in which the film stood in the nitrate hath are due to alkalinity or nitrites, or some impurities in the nitrate hath, and are often met with in an old bath, in which organic matter in one shape or other is present. They may at once he perfectly distinguished from the preceding defects, which are similar in appearance, by being entirely on the surface of the film, and capable of removal by friction. Another cause for the appearance of such marks is the following. When working with sensitive conditions of chemicals, if with deficient quality of light, or small area of size in the subject to reflect hack the pencils of light to the film, the DEFECTS, CAUSES AND REMEDIES. 131 operator should use too small a diaphragm in sta^s proportion to either ; or that the focal length in the camera should he considerable — the darks of the picture are not thrown Avith sufficient vigour on the film to guarantee it from the general action, Ai^hich partakes more of the nature of diffused light than of those distinct pencils of light — with intervals of partial or total privation its conse- quences. of it — which a more complete action would pos- sess j the consequence is, that the lights are not intense, the shadows are weak, and that the drainings of the bath liquid in their course down the film leave traces of their passage. But if on testing, the defect arise from the causes given above, the whole will be found in the body of the film, impressed by the action of light, and not capable of removal by friction, as some parts would be if caused by impurities in the nitrate bath. Distinct smears, with fainter deposit on them, smears, are visible across the subject. They are probably ^ caused by the perspiration on the -hands of the assistant who cleaned them, having found its way first to the clothes, and from thence to the surface of the glasses. The only remedy, in warm weather especially, is to have a good relay of white cotton gloves for him to use. Marks at the top and corners of the subject — Marks of 1 • 1 • ,1 11 . . , drainage, which in the camera was the bottom — arise either 132 MANIPULATIONS. Stains. in camera Tarious. Defective slide. from the film having been too little drained^ and the accumnlation of hath at the bottom during exposure — or from neglect in blotting out the slide between each picture. Both of the above will be aggravated^, if^ in taking the slide from the camera_, it is not carried in the same sense in which it stood, hut tilted or reversed; or if the flap, after the picture is taken, is too violently closed, which has the effect of splashing the liquid collected in the groove upwards over the sub- ject. As with prolonged study, the collo- dion back,^^ or holder, becomes sodden with bath solution. Having to work long and much at one time, two or more backs and inner frames will tell in the improved results. A mark of greater light occurs along the whole of the bottom of the subject. — The light has got in at the top of the slide whilst the film was exposed, showing the necessity of keeping it covered with a cloth whilst in the camera. The subject has a vigorous deposit on the lights, but the shadows are too much filmed over to be bright and telling. It cannot he over-exposed, or the lights would not he so vigorous, it most probably, Fig. 49. DEFECTS_, CAUSES AND REMEDIES. 133 particularly if working with, a double lens^, arises Stains. from diffused liffbt or reflexions. Diffusea ® . liglit. It would^ no doubt^ be the best practice that the lens and camera should be so enclosed that the lens_, through an aperture_, should see only the subject, thereby avoiding all reflexions from sur- Reflexions, rounding light objects^ and giving the purest definition of which it is capable_, but this_, in practice^, is found troublesome_, and loses much time. A much larger and deeper brass shade than is Remedy, usually sold with each size of lens, lined with black cotton velvet (a great absorbent of light) answers every purpose; and has the advantage of allowing the operator much more freedom of action in placing his camera, whilst the shade being on the lens, follows its movements ; when it may be necessary to shift its position in the field, by altering the sliding fronts. Stains of development are, in the earlier part stains of de- . . vfclopmeut. of the photographer’s practice, very annoying ; the most frequent are those of inequality of action, caused by unskilfulness in not covering at one unsUiifui- ness. sweep the whole of the plate, or of not keeping the developer in continual motion, and thus allowing its greasy streaks and stains to impress their image on the film. Using the solution of too great strength will mark a sensitive film by its over-strong solution. sudden and violent action, and the impossibility 134 manipulations. of evening it quickly enough ; lastly, using too small a quantity, in proportion to the superficies of the film, is sure to create stains from its inefficiency to cover the extent of surface. Blank Patchcs of iuseusitiveness, arise in two ways, patches. _ ^ ... hut may each he distinctly referred to its origin. The first are caused in the development, by the operator having poured the solution continuously on one portion of the film, instead of distributing it all over. The result has been that he has washed Silver defi- away the silver, which should have formed the cient m film. from that part, and a hare patch is seen in the film ; hut when arising from this cause there Remedy. is a remedy. Add drops of hath to the developer, and tilting the plate, apply it neatly to the deficient portion, in which the subject will imme- diately appear, and if done skilfully, not allowing the other parts to be strengthened, it will not be perceived in the finished picture, — the same sort of appearance results from keeping the film too Or delay in loug hcforc dipping it in the bath, especially in dipping It. weather ; but there is one appearance which at once marks the diflPerence of the cause, namely, that when arising from this source, iridescent DEFECTS^ CAUSES AND REMEDIES. 135 tints accompany the mark^ which in the other Stains. were not seen^ and the application of the nitrate drops^ the effect of which was instant in the former_, is powerless in this ; the only remedy is remedy, in greater promptness with the next film. The defect caused by the opposite treatment^ namely, dipping the film too soon, makes itself Dipping too .... . . . visible in thickened edges of insensitiveness_, called fringes/^ on the pouring-off margins of the plate_, and a general rottenness and reticulation of the film^ which will probably tear up with the action of the water. Reticulations^ likewise_, are the effects of breathing over the glass, or neg- Effects of lecting precautions in damp weather; water is thereby added to the collodion. This is the reason why, in inferior or unskilfully prepared samples of collodion, reticulation is a frequent blemish, — the alcohol and ether contain water, and we thus per- ceive the necessity of the caution given for their preservation, in perfect order, in small bottles. Hypo stains are of the most formidable and hope- ^ypo stains, less description ; generally traversing the whole plate from the corner where a finger or thumb unwashed, after the development and fixing of the last subject, came in contact with the film. Con- tinuat use of clean water and towel (no soap) is necessary in operating. We have thus examined the various causes of failure in the manipulation of the collodion pro- 136 MANIPULATIONS. Stains. Minute pre- cautions en- sure success, cess, and although many precautions may have been more dwelt upon than their nature would apparently warrant, such minute details are entirely necessary, and if the reader will only strictly adhere to them, he need never .doubt that in taking up a subject he will be secure of an unblemished negative. PART IV. SUBJECTS; THEIR NATURE AND TREATMENT. PORTRAITS. There is no application of Photography which IS more interesting and popular than portraiture ; there is likewise none in whieh many difficult and sometimes antagonistic conditions_, require to he nicely balanced and fulfilled^ if a perfeet result is to be anticipated. When this has been suceess- fully accomplished^ and due artistic feeling in- fused into the arrangement and position of the sitter^ nothing can exceed the interest possessed by a pieture which is the actual reflex of the person represented. Dimension is an important point in photo- graphic portraiture. The exigencies of the lens Portraits. Interest of, and reality. Dimension important. 138 SUBJECTS j Portraits. Rapidity. Consequen- ces of slow- ness. Head alone. prevent us attempting many sizes that would be desirable_, and the artist who undertakes large portraits has various disadvantages to overcome. The focal length of the lens employed is greats and its action slow^ and the sitter’s countenance which^ had^it been taken rapidly^ would have been lifelike, sparkling, and intelligent — no matter what his good looks or otherwise — becomes leaden, vapid, and indeed loses its resemblance to the original ; for the soft and mobile parts of the face, round the mouth — which is the chief seat of expression — have so drooped that their very form has altered during the sitting. Thus photographs which have been attempted, approaching life size, have been most abortive and disagreeable, and heads of three and four inches have not yet been obtained, with the figure and hands in the picture in fair focus and drawing, and when the head alone has been given, the operator has been obliged, in order to obtain any degree of rapidity, to use too large an aperture, and the line of correct focus traversing the face is, on both sides, in immediate contact with distorted forms. When it is desired to take heads of this size it is useless to attempt the hands and figure, the face must occupy the central portion of the lens, and, thus treated, heads of study, &c., can be obtained up to four inches or so. The largest size at which a portrait can be THEIR NATURE AND TREATMENT. 139 undertaken_, that shall include the person and poktraits. hands, is a head about two inches in dimension; Head, hands, ^ and persoM. and we now attain a size which, although difficult and exacting, permits us more freedom of action in the composition of our picture. Lenses of four and a half, five, and six inches diameter, and/oc6?/ lengths, varying from fifteen to twenty- four inches, are required to execute this class of pictures, and the diaphragm must not he more than one half the full diameter if good qualities are desired in the subject, a six -inch lens is quite capable of giving ihe full-length figure and acces- ruii lengths, series with such a head, but the feet being liable to appear enlarged, three-quarters is more recom- mendable, thus avoiding that disfigurement. Pic- conditions tures of this size cannot, however, be undertaken in unfavorable light, as it would then be neces- sary to enlarge the aperture, and the correctness of drawing would suffer. The time of exposure Exposure required will be from thirty to fifty seconds. The next dimension is of one inch and a half to the head ; this picture can either be obtained by using smaller lenses, or retiring the same ones further from the sitter, the latter mode is the better. At this size the full-length portrait can Portraits, be perfectly accomplished, without distortion of the lower extremities, and groups of two or three Groups persons, in the same picture, are capable of being executed. As the increased area of the subject 140 SUBJECTS ; Portraits. Bata for dimensions. Correct re- presenta- tions. Rapidity increased. reflects more light to the lens^ more rapidity of action^ and intensity become perceptible^ and with groups of figures surfaces of twenty inches square can he successfully undertaken. For single full-length figures sixteen inches by thirteen^ or fourteen inches by twelve ; if three-quarters^ twelve inches by ten_, or ten inches by eighty are suitable dimensions. It will be perceived that the qualities of focus and drawing in the picture have become more perfect^ as the size was diminished from the last^ and in this dimension we may con- sider that we have the best average of desirable qualities. As much importance in size as can be photographically attained,, without sacrificing cor- rect drawings and from the power of depicting the whole of the person adding materially to the interest and value of the representation. As the focal length in the camera will have diminished with the same lenses in retrograding from the object, we shall, at this size, gain about a sixth in time of exposure with the same aper- tures ; or if the planes of distances in the subject are not difficult, and we wish more rapid action, the diaphragm may be slightly enlarged, and the exposures to be anticipated in the best conditions of light will be from twenty to thirty seconds. The next gradation is to heads of one inch in size. We now enjoy great latitude in points which in the larger sizes have been difficulties to Smaller sizes. THEIR NATURE AND TREATMENT. 141 contend with ; but, on the other hand, we ap- poetr^^its. proaeh dimensions which are deficient in iin- Appropriate dimensions. portance, and incompatible with many require- ments. The same arrangements of composition can be made, and the appropriate sizes will he ten by eight in full length ; eight by six in three quarters; and six by five in half length. We can now reduce the diameter of the lens employed; three inches is the proper size to use to works of this dimension — diaphragm from two inches to one inch and a half — time of exposure eight to ten seconds. Smaller sizes than the last become of the ut- The smallest sizes, their most facility ; the time of exposure is reduced to facility, a minimum, and the focal depth in the picture is great. They are taken with lenses of two inches in diameter, or with the three-inch combinations removed further off, which, from the greater pa- rallelism of the rays, can he used, if desired, at the full aperture. In the studio small groups can he taken in four or five seconds ; and, if in the open air and sunshine, as rapidly as the lens ean be exposed and covered. It is desirable, if oppor- tunity offers, that the artist should make two or Assays or three essays, at small sizes, ot the subjects in- commended, tended for larger works, which will serve as sketches to show the manner that the light and shade, the positions, and the colours introduced, tell photographically in the picture. 142 SUBJECTS ; Portraits. Exact time of exposure is the next condition Time of ex- to considcT after dimension, and the effect which posure ; its success or failure has upon the picture in giving delicacy and refinement^ or coarseness to the features^ is so great_, that it cannot he over- estimated. The difference it causes can he seen its great im- on Comparing an under-exposed vrork with hard portance ; . outlines^ sooty shadows^ and chalky enlarged features^ without delineation of form/ and one which has been successful^, in which the features its effects on are roiiuded into softness by half tones, and the the picture. _ shadows being reflected into_, appear silvery^ clear, and transparent. The development of the image requires most careful watching, as if the deposit of silver in the film is too weak, the face and hands of the sitter If correct will be dark, and if the development is carried uiriy be de- teiiorated, too far, or drops of bath are added to the solution in order to give solidity and brightness to the high lights, a small excess suffices to render them so opaque that they are deficient in half tones, and that, although the exposure in the camera in developing, was correct, the injudicious development has so loaded the lights as to give the effect of an under- exposed picture. So that we find — besides the condition of our chemicals, and the composition of the picture — in order to produce a perfect portrait, we must not exceed certain limits in dimension, that our THEIR NATURE AND TREATMENT. 143 focus must be satisfactory^ our exposure absolutely portkatts . or nearly correct^ and our development judi- Conditions „ . PI necessary to Clous ; and that a failure in any one of these success, requirements, vrill render the finished work un- successful. Before attempting to place a figure Preliminary for portraiture, the operator should be perfectly acquainted with the qualities of his lens, the size of picture which it gives at different distances, the time, approximately, that different diameters of aperture demand, the degree of flatness or curvature of its field, and the depth of correct focus which it is capable of giving in the subject, which preliminary study can be better carried out its nature, from a life-sized bust, having the quality of im- mobility for comparison of successive plates, than from the life. Having considered all these points we now proceed to take the picture. The first thing to arrange is the nature and Background colour of the background, which should be so managed as to produce a variety of light and shade, taking care also that it composes properly with the dress of the sitter ; that is to say, that a black coat or dress, if placed against a dark ground, would be lost, and the head, hands, and linen, appear as spots ; so if a light or white dress is depicted against a similar tone, insufficient relief and chalky monotony will probably result ; nor is it sufficient to relieve dark upon light or its qualities. 144 SUBJECTS ; pnuTitAiTs. light upon darkj the result of which would be mechanical. There must he a play and variety of light and shade in the background which will give artistic qualities, and which, if judiciously managed, will make the interesting points of the figure or costume salient by opposition, and with- draw from the notice of the spectator any which may be disadvantageous. All this can easily be managed by shading parts of the background and Thesitter of the sittcr^s costumc. There must be a pro- jecting shade of blue calico over the head of the sitter, which serves three advantageous purposes ; namely, to aflPord relief to his eyes, to produce gradation of shade on the background, and more especially to prevent light from arriving in a vertical direction on the head and face; which would give a snowy appearance on the hair and too heavy and dark shadows under the features. Arranging Before tlic sittcr arrives let the camera be in the camel a, about the requisite distance for the size intended, and the centre of the lens at the height of his chin, which may have been previously ascertained : if accessories are introduced let them be analogous to his position or vocation, it will be well that they should all be previously placed in desirable focus, and their effect studied in the and head Camera. The head rest for standing figures is the one described (fig. 30), page 77; it must be wedged under the stand to prevent any tremulous THEIR NATURE AND TREATMENT. 145 motion. On tlie sitter^s arrival endeavour to put portsaits. him as much as possible at his ease. Tuim the studying tiie •*- composiiion. fork of the head rest on one side ; let the sitter stand upright (be sure he does not lean) against the pad of the back rest_, which should touch him firmly_, and against which he may turn rounds as on a pivot_, and change his position till advan- tageous. This arrangement secures the hands, figure, 8 lc., from movement. Now retiring from him^ your eyes strictly in the line of the centre of the lens^ observe the picture — improve^ if pos- sible_, the position of a hand or the turn of the head — note^ that any movement of the sitter^ s head should be very gradual, small alterations Gradual changes. making in the camera much difference ; avoid all appearance of effort in attitude or expression — quiescence or repose is the best ; at all events let both be as natural as possible. Now go to the camera^ the lens at full aperture ; see, on focusing just on his eye, how the arrangement of the sub- ject and figure and the angle of the camera agree with the focus of the mass of the picture; the head, of course, should be pretty good; look to the hands, and if one or both of them are in bad focus alter their position : the nearer the picture is made correct at full aperture the better. The Lens at fuii aperture. accessories can, of course, be moved in any direc- Placing the . , Ml • p accessories. tion that will better their focus. When the com- position is satisfactory come to the front, place 10 146 SUBJECTS ; PoRTKAiTs. the fork of the head rest gently but exactly against the headj screw it firmly^ being careful that it is in such a position as not to show in the picture. If you have a skilful assistant^ capable of pre- Preparing paring the plate_, he should so have timed his the film, 11-1 arrangements as to be now ready^ and on a signal given entering — which will be as well behind a screen_, not to disturb the sitter — having previously and dia- put in such diaphragm as the nature of the sub- piiia^m. light at the moment will dictate, and covered the lens, he puts the collodion slide in its place, uncovers the fdm, and remains ready to remove the cap ; turning his back to the sitter if seen by him. Now quickly, as the collodion will Final scru- not wait, give a rapid scrutiny to the drapery and hands, which if well are better not fingered about, as they become mannered and stiff. Do not let the sitter pass his tongue across the lips, as many have a habit of doing at the last moment, the reflexion of light on the wet surface gives white not colour (see Light, page 13 ) ; it is well Animation that his expressiou should be animated by con- desirabie. ygrsation to the last moment. The picture must be commenced with the de- sired expression ; having got which instantly, but gently, uncover the lens. Watch well the quality Tiie QuaiitieB of the light; blue sky, with white cumuli, are of light. . . what IS most desirable ; north to west the quarter of the wind ; eleven to two the best time of the THEIR NATURE AND TREATMENT. 147 day. It is better to turn away from the sitter^ portraits. as persons looking at him may derange his expression. For such a picture as the foregoing, the flatter the field of the lens, the better, as the accom- panying illustration will show : Observe on Fig. 51. focusing to the eye, the line of principal focus strikes precisely the front of the chest, the head, &c. ; had it been more curved, the hands and person would have been out of focus, resulting in the distortion and enlargement of those parts. If accessories are introduced on a table, &c., the nat field of diaphragm will be exacting ; the advantage of this rabie. three quarter form of portrait, as against full 148 SUBJECTS ; Portraits. Lower parts distorted. Sitting po- suioii. length,, in photography, is that the extreme lower part, which being executed by the margin of lens is the weakest in definition, falls on the middle of the sitter’s legs, where in the costume of either sex there are no forms to demand careful de- lineation ; indeed, whether the folds of a robe, or the uiipicturesque trowsers, it is as well, and throws more interest into the head, that the lower parts should be as it were sketchy ; not so if it were a full length, the feet would appear enlarged under such conditions. Now, in treating this same class of portrait in a sitting position, two conditions diflPer, and must be remarked : first, that the camera should be rather higher than it was placed for the THEIR NATURE AND TREATMENT. 149 standing figure, and dipped/^ whereby it will portrait s take a line of focus more accordant with that of the figure, as shown in the cut. And next that to treat seated figures, a lens of which the field is less flat is ‘positively better, since the so flat a field . Ill desirable. curve includes more advantageously the knees and hands, in this position, than the flatter field of the former lens. It has been recommended to Reflectors, put a sheet or white surface on the ground, at the feet of the sitter ; a very disagreeable light in the eye is the result, giving a sinister expression to the countenance, besides being very fatiguing to the sight of the sitter. It is much better to work with a lower angle of light on his person, and thereby, and by its being sufficiently difiused, render the .shadows on the countenance less harsh. The best light for portraiture, is the quarter of The most _ -vT T advantageous the compass from N.W. — N., to N.E., and to /Ac eye the eflPect of light and shade on the sitter’s face should be so gentle that the shadows are hardly defined; the collodion film being very sensi- tive, appreciates their gradations more readily ; if they were seen on the face as they would be desired in the picture, they would appear in the Appearances finished work with dark and Carravagio-like effect, ill fitted for portraiture, and only permissible in heads of study. 150 SUBJECTS ; Groups. Previous sketch (Ic.- sirable. Dimension studied. Lens se- lected. TAKING A GEOUP OF SEVEEAL FIGUEES IN THE STUDIO. Before attempting tliis^ the most difficult operation in Photography, it is necessary to study several preliminaries. It wiU be highly desirable that the operator should make a sketch of the proposed composition, always bearing in mind, in so doing, the exigencies of focus. If he be judi- cious in his arrangements, there is nothing what- ever to prevent his having the satisfaction of seeing his conception perfectly realized by the camera, with such delicacy of finish as Nature^ s handling is alone capable of. His sketch being made, he must now decide at what size it will be judicious to execute it, not forgetting that certain distances in depth, from front to back in the subject, will only admit of equivalent limits in the dimensions of the picture; and that by attempting large sizes, with deep compositions, defective definition will be sure to result. He must remember that focus is the penciFs-point in Photography, and that it wiE be impossible to make a perfect work if it has been neglected. Having selected such lens as may seem best adapted to the dimensions proposed, of which an THEIR NATURE AND TREATMENT. 151 approximate guide is given at tlie end of this groxjps . section, he must fix his camera opposite the place where the subject is to be composed, and at such distance that the area necessary to contain the intended group just fills up the space allotted to it in the camera; he must take care that the camera is at right angles with the subject, and he must now ascertain the line of principal focus at full aperture of his lens, through his picture, taking a point near the centre for the most in- teresting objects in his composition, as there the correct definition of his lens will he greatest ; he will place numerals, as described at page 43, on the curve of the focus, and marking the results on the ground, be enabled at once to place the still- life, background, &c., and to arrange for the subject „ . , p . arranged. figures in the most favorable situations, to com- ply with those exigencies by which he is re- strained; remembering, ^‘^Ars est celare artem,^^ and that no traces be observed, in the resulting picture, of his careful management. As he pro- ceeds in the arrangement of the composition, it will be well for him to refer continually to his camera, at full aperture y to see how the important parts of his subject stand relatively to the prin- cipal focus ; noting, however, that the focus will be deepened and the definition improved, when he shall afterwards put in such diaphragm as may Diaphragm, be judicious. It will be well that the background 152 SUBJECTS ; Groups, sliould bc in Icss pcrfcct focus than tbe principal objects in the picture,, but not too much so. If the persons are at hand^ who are to be introduced in the composition^ or if there is a lay figure and some of the draperies which are to be used^ a trial negative may be taken,, which will show Photografldc if the colours are photographically desirable,, or skcl/Cli. the contrary ; should either some isolated objects in the picture^ or larger masses of the com- position^ require to be lighter or darker^ use may may be made of the following expedients : firsts Expedients for Small portiOTis. Furs, rocks, stones, hair, to alter parts. hands, or complexions, leaves, grass, earth, car- pets, &c., may be lightened as much as necessary by a powder-puff, directly applied, or shaken a yard or so above them, so that an atmosphere of extremely minute white particles shall settle on them — chalk or whiting may be lightly smeared on iron work, carved wood, or other surfaces, &c., or a stiff ^^hog tooF^ may be used to those or other surfaces with powdered chalk ; larger parts may be tinted wet with whiting and lamp black to any tone required; or to darken take burnt umber and lamp black, and apply dry or wet as directed previously. To change If large povtions of the composition would be larger masses. 'ke^t dowu, a blind or curtain, either opaque or semi-transparent, as thin muslin, may be in- terposed between such parts and the light, and by THEIR NATURE AND TREATMENT. 153 various trials of sucli effects on different parts of ORorps. the composition very fine results may be arrived at. Should parts be too obscure^ white paper^ sheets, or looking-glasses may be used to throw light and reflexions into the picture. The so- called daylight reflectors^^ are useful for this uayiigiit ° ^ reflectors. purpose. Arrangements must be made to give the sitters support during the sitting, without such necessary aids to their steadiness being ap- parent, or in any way interfering with the free- dom and nature of their positions and expressions; sometimes, if the attitude be not difficult, a very small matter will suffice — anything rigid that will prevent the sway of the body. Having thus suf- ficiently prepared the subiect, the actual execution ar- o ■> rangeruents. of it arrives ; here the greatest attention will be required that the draperies take a proper arrange- ment of folds ; that the positions of the bodies, heads and hands, and more than all, that the expressions of the countenances are as they should be, for it suffices that a finger be disagreeably placed to spoil the whole as a perfect work ; and this, when several figures have to be treated, apart from all difficulties of manipulation, may well explain how far approaches to anything like satis- factory results are seen in this department of Photography. The size of aperture to be em- Precautions, ployed with the lens must be regulated by several conditions ; the depth of the picture, the quality 154 SUBJECTS j Gkoups. Diminished aperture. Increased, and why. An assistant desirable. but can be dispensed with. of the lights the nature of the positions and ex- pressions are the chief points to consider. The con- ditions which will demand or admit of a diminished diaphragm are — perfection of light, shallowness from front to hack of the subject, and positions of an easy character; as for instance, sitting, well sup- ported, and the eyes not turned fatiguingly to the light; such diameters of aperture will always tend to give much greater refinement of definition and beauty to the drawing of the objects repre- sented, but are incompatible with bad or indif- ferent light, a deep composition of picture, and positions or expressions of countenance which the sitters could not maintain without a visible ap- pearance of constraint. All these points having been considered and provided for, it will be better that the sitters should not be retained in their places, until the collodion film is taken from the bath to drain, which will prevent unnecessary and deteriorating fatigue. Of course it is in many respects better that an assistant should prepare the plate, leaving the artist entirely free to arrange the picture ; but to show the student that it is not absolutely necessary, it may be stated that groups of several figures have been arranged, the whole of the manipulations performed on plates of some size, and several negatives, with satisfactory expressions, produced entirely without assistance, within the hour. The great point in THEIR NATURE AND TREATMENT. 155 such compositions is to see, before uncovering the groups. lens, that not a hand or drapery is misplaced, leaving the expressions to the very last moment, when they are satisfactory — of which the artist must assure himself very rapidly — gently, hut quickly, uncover the lens ; it is better to maintain perfect immobility, and on no account to allow any spectators of the operation, who may readily, by their presenee alone, spoil all. It is surprising what a wide scope for the artist Nature of . . - . ^ 1 subjects. exists in this department of Photography ; a ^priori, it would be supposed that he would be limited to the mere representation of an angle of a room, with any additions in the shape of furni- ture, &c., that he could introduce ; such, however, is far from being the case, a vast variety of varied and numerous. subjects, or portions of subjects, as studies, are within the powers of Photography in this depart- ment j indeed, it might be said that almost any description of group or composition might be successfully represented by means of a little study and ingenuity. Water, rocks, foliage, flowers, plants, fish, game, and any other still-life, analogous to the matter on hand, may be so arranged with the figures that the subsequent observer shall not have an idea that the picture was composed and treated in the studio. By varying the light and shade on portions of the composition by blinds, or moveable 156 SUBJECTS ; Groups. The proper lenses. Some data for lenses. frames of yellow glass_, most instruetive and interesting results may be obtained^ and such varied eflPects of cMar-oscuro on the same subject would be most useful as studies and appreciated by all artists. These pictures can be treated up to twelve by ten inches^ either with the single or double lens ; the qualities of the first are larger sizes of the objects rendered at the same diameters and dis- tance from the subject, longer exposures, and less intensity and rotundity in the picture, but the writer would recommend the double combinations in preference, since the foregoing are a class of compositions which must be treated in the glass studio, and consequently out of direct sunshine. The modified light, though sufficient for the action of the double, is slow with the single lens, and beyond a diameter of three inches such lenses become, from their focal length, too slow, and are not proper to attempt. The dimensions of double lenses, relatively to the sizes attempted, are three inch diameter for eight inches by six inches; four and a half, for twelve inches by ten inches; and five, six, and eight, for larger works : the apertures used, and time of exposure, depending upon the qualities desired in the finished picture. THEIR NATURE AND TREATMENT. 157 RUSTIC AND PICTURESQUE FIGURES, Whether singly or in groups, differ from por- traiture and subjeets of refinement in this impor- po®fai?uT™. tant partieular, that whereas the latter are obliged to be taken in a tempered light, in order that the shadows on the faees may be softened, and the features as delieately rounded as possible ; the whole of the subjeets comprised in the title Rustic and Picturesque figures, gain in character and vigour by being executed in open sun-light, can be taken provided that the shadows are treated with sum- ligiit- cient skill to prevent their degenerating into heavy black masses without reflexion. This is photographically advantageous, since the increased power of illumination allows the picture to be taken very rapidly, thereby avoiding the blemishes that it would show in a more prolonged exposure, with sitters often intractable and ignorant. It will be advisable that the operator should give considerable attention to the Attention to . 1 selection and grouping and arrangement ot his materials, so arrangement, that they may have a natural and pleasing effect ; The method, the best method for him to accomplish this, is to watch a group when they are not conscious of his observation, and when subsequently setting them. 158 SUBJECTS ; Eioukes. Eorm desira- ble studies. Taken in na- tui’al groups. Not staring at tke lens. Generally in- structive and interesting. or similar figures^ for the camera^ to endeavour to reproduce what he has previously noted. So little has yet been seen in this class of subjects, that it may almost he considered untrodden ground^ and a rich harvest of admirable material presents itself to the discriminating operator in every loca- lity. With proper selection^ the most interesting and useful studies can be collected_, whether by the military and naval services, the tourist and traveller, or the more stationary photographer* It matters not whether the subjects represented be taken from our own fields and shores, or from more distant and, to us, more interesting, locali- ties ; the truth and exactness with which they can be rendered by Photography, will insure their being generally appreciated. What is most requisite is, that the figures composing such groups should have an air of natural occupation, as if in their usual vocations or amusements. When, heretofore, they have been attempted by amateurs and others, they have been shown as a stolid half circle of gaping figures, intently staring at the lens. Now it must be evident that such a picture can excite no feeling of satis- faction, even in persons of the most uncultivated tastes in art, who are, however, not slow to appreciate the merits of more tasteful selection and arrangement. It is very desirable, and adds much to the interest and instruction of such THEIR NATURE AND TREATMENT. 159 pictures^ if the dwellings_, implements of their eigu^ calling, the animals they employ, their trappings, and the vehicles of the different countries, are represented in the same studies as the figures. If thus arranged and treated, it matters not Suggestions whether the harvest-fields or hop-pickings ofgraphers. England, the posadas or sierras of Spain, with their Murillo-like beggars, their trains of dusty mules, and gaitered arrieros, the noisy and many- coloured zoc of Tetuan or Tangiers furnish the subject, cr whether the narrow streets, crowded fountains, or rich bazaars of Cairo and Con- stantinople are realized, or if the mail-clad warriors of Circassia, the tents of the Bedouin, and the endless variety of picturesque costume of the East are represented, — all are interest- ing, instructive, and highly useful in many di- rections. The lenses employed for these subjects are Data for the •1 1 instruments. both the single and the double; the first when larger dimensions are desired, and the operator is sure of his sitter, since the time required will be greater ; the second — and at large apertures — when many individuals, children, animals, &c., are comprised in the composition, which would necessitate a treatment approaching the instan- taneous. Three and five inch lenses, both land- Sizes of lenses scape and double combinations are excellent sizes 160 SUBJECTS ; Figuhes. A desirable condition , generally ap- plicable, to use^ and with them fignres_, varying from the smallest dimension in an instantaneous distant- group, to single figures of fifteen inches in height, can he obtained. INSTANTANEOUS PICTURES. If there is one direction more than another in which we may look for greater artistic excel- lence and interest to be imparted to the photo- graphic picture, beside judicious selection and tasteful arrangement, it will be by the process being so much accelerated, by optical and chemi- cal improvements, that any dimension and class of picture may he taken instantaneously; nor need we despair of witnessing this result, when we see what progress a few past years have brought with them to this art. The benefit to be derived from an instantaneous picture, is equally great for every subject taken from nature by the camera, with the exception of still-life, and mere geometrical architectural eleva- tions ; here, as everything is fixed and stationary, the smallest possible apertures, and longest de- sired exposures, may be employed ; and in this direction we may presume that nothing more is to be expected. But astonishing as the quality of THEIR NATURE AND TREATMENT. 161 definition may be under sucli conditions^ is instan- . TANEOUS. obtained ; the result is often cold and mechanical ^iiere most from want of selection in the point of view and deficiency in qualities of composition of line and light and shade^ and therefore not possessing the interest that the smallest subject taken at the hedge-side^ or on the sea-beach would have. It is by the rendering of the vivid expressions Subjects to ^ be treated. of heads taken from the life, of the perspective view in the crowded city, with all its incident of passing and moving life, of sea and river subjects viewed in calm and storm ; in the first, the white cumuli piled up, their snowy masses delineated, to the depths of the cloud, the idle sails flapping on the masts, the bright reflexions from both on the . . . . Marine. water, full of drawing and rippling in the light breeze; or the sombre rocks, or haven^s entrj^, with the sharp surges dashing on them, the keen wind felt in every form of the moving waves ; the fisher-boat’s dark hull rising on the crested sea, dashing the white foam from her bows, the strain- ing lines of her sails and gear yielding to the blast. In the landscape, the sky, one of the chief Landscape, components of its beauty, will not be a white blank, but by its lights and shades will give charm and value to the whole composition, and waving branches and moving leaves will cease to be curious mystifications. Views in distant and picturesque cities will not 11 162 subjects; Instan- taneous. Disadvan- tages of long exposure. Moderate sizes witli present means. Favorable conditions. seem plague-stricken^ by tbe deserted aspect of tbeir streets and squares^ but tv ill appear alive witb tbe busy tbrong of tbeir motley populations. All these subjects and many others will be glorious things to look upon^ when they shall be rendered perfectly by Nature^ s own drawing. Shorten the time which the nervous sitter has to remain under the mesmeric influence of a gigantic glass eye^ and you will see his contracted and rigid features expand^ and a genial light diffuse itself over his face^ and life and nature will be worthily represented. Much of the foregoing is even now in our power to realize,, but with our present limited re- sources we must be modest in the sizes we at- tempt; size alone,, in a photography when unac- companied with high qualities of other kindsy only serves to make more visible the falling oflP from the excellence to which we should have attained. Large sizeSy from the increased time required for their productiouy are obviously a mistake in this class of subjectsy which will possess admirable qualities even if of the smallest dimensions. The great Turner^ s magical and lovely vignetteSy which alone would have formed a colossal reputa- tiouy were not so large as the palm of the hand. To take instantaneous picturesy we require first favorable conditions of lighty atmosphere and tem- perature. We must nexty by judicious selection, THEIR NATURE AND TREATMENT, 163 endeavour to secure equable balance of light and instan- , , T /> ■, . TANEOUS. shade and of distance^ ii the extremes are too great in either failure will probably result. For example^ in the first, a chalk cliff in sunshine, with dark Unfavorable rocks in shadow at its base. In the second, ob- jects as foreground taken too near the lens, and included in the picture with extreme distances; the result of which would probably be, that at large apertures — which the manipulation necessi- tates — the two extremes would not come out per- fectly; if the development was continued until one part was satisfactory, it would be at the expense of the other. The class of subject the best adapted for this Desirable subjects. treatment is the marine — in it a more even ba- lance of light and photographic action exists between the sky and the water which, with all its markings, will come out as rapidly as the sky itself. River scenery ofPers more hinderance than other landscape, as the greens of the foliage, and the blue and grey reflexions of the sky on the surface of the water, have very unequal action; and a development which shall suit both is diflicult: avoid taking such subjects looking towards the Suggestions, sun, as then the trees will be black masses with- out any drawing. Animals are very interesting objects for study by this process, and although very successful representations of them have been made, there is still much opportunity for 164 subjects; iKSTAN- developing the capabilities of the art in this TA>‘KOIjS. direction. Tiiechemi. The Operator’s first care must be that the chemicals to he employed are in the most perfect condition ; the hath used should in cool weather he ioHj, in warm thirty grain solution. It will be well to have at hand two or three samples of collodion^ more or less recently iodized ; the developer^ newly prepared^ is to he used at the full The lenses, strength of the three grain solution. The lenses proper for the purpose are the double combina- tions ; the three and five-inch diameters give good pictm’es ; the first will cover eight inches by six^ the second twelve inches by ten_, if they are of good quality^ with the three inch a two inch aperture^, with the five a four inch aperture^ have given pictures^ in a London atmosphere_, of re- markable qualities. Yehicles and animals in motion^ pedestrians_, their costume blowing in the windj have been developed on a foreground in which every pebble was defined with a minuteness the longest exposure could not surpass. Treatment in If the picture dcvclopcs wcak and rather developing. clcar it as described^ page 109 ; if weak blit not fogged, add bath to the developer^ or use solution_, one grain chloride of gold per ounce^ aqua distill., to strengthen the image. Instantaneous To uncovcr thc Icns thc contrivance shown in the diagram is recommended, having the advantages THEIR NATURE AND TREATMENT. 165 tliat it leaves the operator at full liberty to watch his subject^ and by pulling a string at the moment he judges opportune taking the picture. The falling slide can be screwed on at « « to the front of any camera^ b ; the lens operates through the aperture a; the slide, when draion up, covers it with the bottom portion c ; now, on relieving a catch it falls by its own gravity — the most even and instantaneous motion possible — and the open- ing in the centre allows the lens to see the subject for a distance varying from half its diameter to two diameters, according as the two shutters d d may have been adjusted with their respective screws b h, this alteration in the aperture regulating the degree of exposure of the subject. The same result oan be arrived at by the rotation of a disk of thin metal or of wood, centered in a similar manner to the diaphragm plate of niicros- Instan- TANEOUS. De?ci’iptioii of its action. Another lueihod. 166 subjects; Instan- taneous. Before or be- hind the lens. Faulty ar- rangement. Anticipated advances ; possible wii present means. Beautiful in details. copes^ with a strong spring of vulcanized Indian- rubber attached ; on releasing a catch the rotation of the perforated disk will cause an aperture of greater or less size to pass the lens. This arrange- ment may he made either in front, or within the camera behind the combinations. The mode of exposing by the cat^s-eye principle is faulty_, inasmuch as it gives a longer exposure to the centre of the lens_, thus increasing still more the unequal action already existing between its definition and that of the margin. As has been previously mentioned we must anticipate great advances in all directions in Photography_, and no doubt the sensitiveness of the chemicals will he much increased; but even with the means now at our printing nega- tives of moderate dimensions can he taken in the fraction of a second^ perfectly representing the various objects seen in nature^ whether in motion or not. It suffices that the operator should give considerable attention to the condition of his bath. &c._, to secure a satisfactory result. LANDSCAPES. The photographic landscape^ judged by the rules of arL is yet far from being a perfect work. It presents to the spectator many charming parts, but taken as a whole it is defective as a picture. THEIR NATURE AND TREATMENT. 167 The sky^ that principal point of the landscape NDSCAPES painter^s selection and care, in the photograph has no existence, hut remains a blank. If a river skyandwater wanting. or water in any of its many picturesque combina- tions of lake, falls, &c., enter into the subject, the treatment of it by lengthened exposure in the camera, becomes a photographic conventionality, with certain smudgy reflexions in the one case, and woolly looking white patches in the other ; wanting entirely in the drawing of the ripple of the near water, the beaming light or passing shadow of mid -distance, or the sharp sparkling dash of the mountain stream. The trees in most other draw- backs. instances have waved their branches backwards and forwards during the execution of the picture, and on what should be their delicate and feathered margins, enigmatical forms are found. These points render photographic landscape seldom quite perfect as a whole, though exquisite in the detail of its parts j and when by dint of careful selection and study, anything approaching a satisfactory result is attained, it should be valued in proportion to the difficulties overcome. Generally speaking, the subjects which will offer the best conditions to the camera, are those situate amid mountainous scenery, as Tyrol, Norway, Switzerland, Wales, and the Highlands of Scotland, for the reason, that the height of the distances dissimulates the want of sky, and, 168 SUBJECTS : Landscapes indeed^ as they are full of suffieing forms and drawings are better left in repose. The masses of roek in the foreground and middle distanees are rendered by the camera in a manner which leaves nothing to desire^ and the whole being composed of rigid forms, any degree of desired definition may be attempted with probability of perfect success. Injudicious Thc subiccts which are least adapted for the subjects. ^ ^ camera, are views on plains, over sands, and generally all subjects of low horizon, m which the sky or water form a large portion of the picture. When trees are introduced, calm days must be selected, as then there is little or no movement in their branches ; or situations chosen — such as glades in woods — where shelter is afforded by Portions as the contiguity of masses of foliage. Picturesque bits’^ of landscape, with water and other mills, ruins, cottages, &c., selected with care will come well, these objects giving point and incident to the subject; a large field is yet fallow of studies of useful details of foreground, for the treatment of which the camera is eminently qualified, and such subjects will be very useful to art. If in photography the entire landscape is to be attempted as a complete work, which shall satisfy the critic, it is to the instantaneous process we must look, if even the result, as regards size is limited, as by that treatment alone the combi- THEIR NATURE AND TREATMENT. 169 nation of sky witli liill and dale^ and river or lake^ laxdscapt?s will be obtained^ and all tlie captivating efPects of passing cloud shadows, and gleams of sunshine on -1 Sky, water, different portions of the landscape represented, and cloud These are effects of light that have never yet been presented, photographically rendered, and the difficulties are of course greater from the greens of foliage offering impediments to rapid exposures, but which, however, at moderate sizes, are not insur- mountable if skilfully treated. The student should note distinctly, that however astonishing and captivating extreme definition and detail may be in studies of foreground, &c. ; in dSaiL the general landscape, fine broad effects of light and shade will supersede it all. Mere clean mechanism on the plate grows monotonous, and wdll always succumb to the sentiment conveyed to the mind of the spectator by representations — pho- tographically less perfect — in which any of the changing effects of light and shade may have been successfully rendered. The artist should likewise consider that careful and discriminatinq selection Tasteful se- lection neces- wdll make itself felt in this, as in every other description of subject, and must not go out with his camera as to a sort of photographic battue, in which 07ie well studied picture seems not to be the desideratum, but quantity not quality is sought for. Now, the truth is, that one little bit of well 170 SUBJECTS ; L ANnscAPEs selected fore-ground^ a bank with a few docks and thistles^ with the bright sun-ray glancing from the tufted grass to the gray ivy-grown stump of the gnarled pollard, is worth a hecatomb of such things. The execution of landscape pictures entails the necessity of having a tent, van, or some other means for the manipulation of them, since none of Disadvan- thc drv proccsscs^^ arc sufficiently sensitive to processes, attack the recalcitrant greens’^ of landscape with anything at all approaching the power and sensitiveness of the ordinary wet collodion. Whilst at the same time the operator may, in these railway times, be some two or three hundred miles distant from the pet subject of which he fondly imagines he has a transcript, borshown of which illusion sub- sequent development proves the fallacy ; the only certain way is too see the result before leaving the spot. The objection to the tent is its want of rigidity, and itself requiring a separate package. The woodcut shows the construction of a box which contains the whole of the photographer's material of Camera, lenses, baths, &c., and at the same time opens into a rigid and sufficing operating space with shelves, sink, and every necessary appliance, and has been in practice found to answer most admirably up to sizes of twelve by ten, which, with the minute qualities of THEIR NATURE AND TREATMENT. 171 photographic representation is really large enough lam?scapes for most subjects. Fig. 54. The lenses proper to employ for landscape pic- j^wropnate tures are both single and double; the first to be used when the subject is of that nature that some size is required^ and that it wiU not suffer by a lengthened exposure; the best diameters are two and a half^ three and a half, and five inches^ covering respectively eight inches by six, twelve inches by ten, and sixteen inches by twelve ; the 172 SUBJECTS ; Landscapes Action of diaphragm. Danger of fogging. Distance and loreground. Working towards the sun. aperture to be used will be better small if the subject is well illuminated^ since under that con- dition the extreme planes of distance will be more perfectly rendered. The double lenses employed should be three and five or six inch diameters^ and they will give pictures of very various qualities according to the diaphragms used. When extremely minute detail of foreground is desired they should be stopped down^^ to an aperture of one inch_, and for this purpose the diaphragm is better placed before the front lens^ which it shelters from the action of diffused lights as if placed between, unless great precautions are taken^ a fogged picture will probably result. The difference of quality between the two in such a subject is_, that the double combination has realised all the forms in a more clear and vigorous manner^ and given much more definition than the single. At large apertures the difficulty is to bring the two extremes of the picture into harmony; but many depths^ in masses of foliage^ which were bare glass and quite intractable to the single lens^ even with prolonged exposures_, are worked into and filled with half- seen forms by the double com- binations. Many very charming effects of aerial perspective^ marking the different planes of dis- tance, in undulating or mountainous country, are obtained by working towards the sun — this must be done when it is not too near the horizon, as THEIE NATURE AND TREATMENT. 173 then the light would look directly into the lens, landscapes S uch treatment of the subject requires precaution to avoid fogging; it is well to shield the lens_, whether single or double^ by a dark cloth^ which can be held above it. If the student has no previous knowledge of Precautions, artistic treatment of landscape,, he should make himself familiar with the works of Claude,, Turner,, Ruysdael^ Hobbima, Both^ and our own great living talents in this department; as has been previously said^ mere skilful mechanism will not suffice ; if Photography is to take stand as an art Cultivation of those who practise it must qualify by study for ^^ecessaiy. artistic requirements. A short time will suffice for an intelligent mind to imbue itself with as much knowledge of the subject as will prevent egregious blunders ; careful practice from nature will do the rest. ABCHITECTUEE. Of all the subjects offered to the camera^ none Facilities of execution. are so facile of execution as those from architec- tural originals ; their rigid and immoveable forms, the large area of the surfaces reflecting light to the lens, in open air and sunshine, present advan- tageous conditions, which enable larger sizes to be covered, smaller apertures to be employed, and longer exposures to be given, than any other class of objects. 174 SUBJECTS j archttec- It majj indeed^ be said_, witb considerable con- TURE. “ fidence^ that in tbe close imitation of tbe originals, a limit bas in this direction been attained, which it will be difficult if not impossible to surpass. Mechanical At the Same time that we feel that the mecha- excelleuce. nical excellence shown in these subjects has been such as to delight by its clear definition and precision, regret has been experienced by artists and amateurs at the mere geometrical ele- vation’'’ effect which has characterised some of the best subjects hitherto executed, and which rS? ^ rendered them much more fitted as documents qualities. officc of the architect, than complete and agreeable as 'pictures to the lover of art. In looking at a series of architectural photo- graphs of the foregoing description, it is impos- sible not to wish for the completion of the subject by the selection of a more picturesque point of sight, the infusion of more artistic qualities into its composition, and its completion, as a whole, by the representation of that foreground and accessories which in nature made it captivating by contrast, and formed a base from which the edifices represented rose. alone not The mere size of some of the large subjects of sufficient. architecture, does not compensate to the artist for the loss of those incidents of composition, and qualities of light and shade, he would have THEIR NATURE AND TREATMENT. 175 preferred seeing in the pietnre^ and whieh at auchitec- TURE. less dimension^ were quite within the scope and province of the lens. If very large sizes are undertaken^ they are of necessity from 'plane or nearly plane surfaces,, the wondrous manner in which the lens draws every minute break,, angle,, or varying surface in the perspective view is not seen, and though our first Lose tiidr 7 . . . . . . interest. impression is surprise at the dimension attained^ our subsequent feeling is indifference to the subject, which, by its mechanical treatment, ceases to interest as soon as its mere novelty has subsided. Medium sizes, therefore, are desirable, which shall enable the photographer to produce pictures having the composition of line, and qualities of light and shade we are accustomed to admire in the works of the painters who have treated this class of subject. The photograph possessing in Qualities . . . , desirable. addition, the interest given by its being the actual reflex of most interesting localities, and the gratification imparted by the delicacy and minuteness of its execution. The mediseval remains of our own country. Applications historically so interesting to us, the florid Gothic edifices of Spain, her mauresque architecture, the intricacy of whose details bewilders the eye of the draughtsman, the cinque- cento arabesques of Italy, sculptured in marble with an artistic grace and 176 SUBJECTS ; akcbitec- finesse wliicli defy the pencil^ all can^ with the TIKE. ,,,, „ utmost facility^ be rendered by the camera. We have^ indeed^ had evidence of what it is capable of to subjects, producing in the Egyptian pictures lately ex- ecuted^ and we must hope that well directed study on the part both of professors and amateurs^ will give us further interesting and useful subjects. However, in whatever manner they mav be Eacilities for study.. treated_, it is certain that the facilities for near comparison and study given by photographic transcripts from remarkable architectural ex am- plest will produce as striking results, by the advancement of taste and knowledge, in this, as in any of the applications of the art. In the earlier practice of photography, the single lens alone was employed to execute this class of subject; latterly, some of the most perfect representations of edifices have been made by using the double lens, at very small apertures ; there is much more rotundity and realisation of the forms of the subject in the latter mode of treatment. The size of lenses employed, if double combinations, is considerable when large pictures are desired, six and eight inch diameters were used for some of the elevations of portions of the Louvre. The single lens giving a much larger picture, at the same diameters, has the advantage of greater portability for the amateur. "Double lenses. Data for sizes. THEIE NATURE AND TREATMENT. 177 who would find an eight-inch double lens a archttec- , . TURK. cumbrous companion. When the operator desires to produce a minute Geometrical ... p /II n T /• elevations. representation ot a flank ot an edifice^ as a geometrical elevation^ the mode of proceeding is as follows. If windows in buildings immediately opposite permit, endeavour that the lens shall be placed at about one third the height of the subject, instead of on the ground, whereby the proportions will be better observed in the picture. Carefully level the camera with the spirit-level. Mode of . T 1 T treatment. to preserve the lines in the perpendicular, and use the smallest diaphragm the nature of the light will allow. These pictures^ will be perfectly calculated for the use of architects, as if skilfully taken they may be considered as exactly drawn to scale. If it is desired to produce works of a more picturesque artistic character, in which various masses ofSs.^°^ buildings, at different planes of distance, are intro- duced, less dimensions must be attempted; in some such subjects, as for instance, views of Florence looking down the Arno, of Paris from the Seine, &c. ; the want of figures in the picture is not so much felt as when the squares and streets of populous cities are represented ; here, if anything approaching the appearance of the complete originals is to be shown, it can only be by com- bining in the picture the moving panorama, and 12 178 subjects; Akchitec- TUKF. difficult of treatment, but possible. Different classes instan- taneous, not giving a Pompeian aspect to tlie most crowded and busy tlioroughfares. For the firsts single or stopped down double lenses may be employed indifferently ; tbe resulting pictures will be dis- tinguished by the less size^ and greater definition in those taken with double lenses ; for the second double lenses can alone be used. The operator must avoid large masses of shadow^ and if skill is shown,, pictures of twelve by ten inches may be thus obtained^ not but that very considerable diffi- culties must be contended with and overcome; but if a picture is to be presented to the spec- tator^ of this class of subjects,, which shall impress him with the aspect of the original^ as seen in nature^ it is to this treatment alone we must look for success. MARINE SUBJECTS May be separated into two classes,, afloat and ashore ; it is needless to observ e that the only treatment to be adopted with the first is the instantaneous ; and these subjects,, even with the means the optician and chemist have already placed at our disposal^ are quite possible^ and only want proper artistic selectioUj and sufficient photo- graphic shill to reward the operator by most interesting pictures. THEIR NATURE AND TREATMENT. 179 The same caution which has been elsewhere given makint , , , , SVBJKCTS. must here be repeated^ not to attempt too large dimensions^ twelve by ten, or ten by eight, amply suffice ; and it is much better that at those sizes at moderate dimensious, a picture should be produced possessing any perfeet qualities of daylight, atmosphere, &c., than by attempting sizes that are not within the power of our present resources, to hear the pic- tures qualified, as that clever moonlight/^ as one of the best examples of this application of photo- graphy, habitually is by the general public. Mai’ine subjects on shore may be treated by by longer longer exposures, and with either the single or double lens, they comprise fishing cobles and other tbeir nature, small craft, capstans, buoys, anchors, and all sorts of picturesque fishing and sailing gear, lying on the rocky or sandy beach ; and, combined with them, it is quite within the scope and province of such a photographic subject that groups of analogous figures, which are always at hand, should be introduced ; observing only the caution given in another place, and make the picture if possible, tell a story, or at least let its figures Suggestions, have their occupation and attentions ivithin it, and not directed to the camera. 180 SUBJECTS ; AjilMALS, Eapid execu- tion neces- sary. Artistic interest. Desirable precautions ANIMALS. A class of subjects which has been little treated by photographers^ and which yields to none in interest^ are animals from the life. They of course present insurmountable difficulties for any mode of treatment which implies a lengthened time of exposure^ but most exquisite things, of a limited size it is true, are quite within the power of the operator ; and by taking them in full sunlight, with rather large apertures of a double lens, pictures may be obtained which possess high qualities of artistic interest. It is well, in treating them, that an arrange- ment should be made, whereby the operator and his apparatus are entirely hidden from the animals, as otherwise, his advance to the camera, the act of uncapping the lens, his every movement, will cause the ears, eyes, and heads, at the least, to be defective in the picture. This is very easily managed, by a canvas screen of small size, supported at each end on sticks, with pegs and strings to give it firmness, and an aperture in the centre only large enough for the lens to pass through. It will, in most cases, be mueh better if a contrivance for uncovering the film to the action of light is made inside the THEIR NATURE AND TREATMENT. 181 camera^ behind the lens_, as thus aU movements animals . that would disturb the animals are entirely avoided. If the lens has a projecting shade over it_, the chance of fogged pictures from the action of reflexion on its large uncovered surface will be diminished ; whilst at the same time — as it will be more concealed — horses and shy animals taken “^ove- ments of the at near distances^ will be less alarmed by its bright- ness. It is likewise an excellent expedient to place small branches of foliage^ trusses of hay^ or any familiar objects which may happen to be at hand, against the canvas. A black curtain, excellent for many other purposes, may do duty on this occa- sion for the screen ; the dark colour, so far trom being objectionable, is better than a lighter for several reasons. The same result may be arrived at by taking taken from a carriage. them actually from the photographic carriage, which in some cases, as deer, &c., will be found convenient, as they may be followed. Eemark only, that just before taking the picture it will be neces- sary, by the insertion of wedges of wood, to neutra- lize the action of the springs of the carriage, or the image will sufier j also that the aperture for taking the picture should, by its distance from the ground, correspond to the average height of the human eye, otherwise the picture will appear unnatural ; as if it is taken from too high a point of ’view, the animals will seem to be looked down 182 SUBJECTS ; Animals, Pathology. Powers of delineations. Skilful ma- nipulation. Pathological application. Studies of morbid struc- tures. upon. The arrangements for bath, collodion, de- veloper, &c., must be precisely similar as for instantaneous pictures. PATHOLOGY AND CHIRURGERY. Photography has not yet been so generally ap- plied to depict the phases of disease, and delinea- tions of morbid structure, as it doubtless wiU be. The nature of the medical student’s education eminently fits him skilfully to utilise its powers in various directions connected with his study, and the few applications that have been seen by the public — amongst others, the characteristics of mania, in its different stages, by Dr. Diamond — show the assistance that it will be able to render to science in this department. Doubtless before long it will be rare to find a public institution in which the most instructive cases are not daily noted in their progress by Photographic means. For this portion of its application quick-acting” double lenses will be required, siuce the nature of the light used would be exacting; s/iorf focmed three and four and a half inch diameters would, even in such localities, give pictures in a few seconds. Studies of the osseous structure may be treated at considerable sizes by the single lens, and the THEIR NATURE AND TREATMENT. 183 delineation of the niceties of form is most remark- pathology . able; it is only necessary to have seen photo- graphs of portions of crania to feel what its powers of realization are. Preparations^^ offer more or less difficulty to Photographic representation ; if^ from their nature^ various treatments. they are intractable to the action^ double lenses_, at small apertures^ with long exposures^ should be employed, and a direct vertical light avoided. STATUES, BUSTS, BASSI EELIEVI, AND BEONZES. The above objects are amongst those which Statues, Scc. offer few difficulties to the Photographer — neat and careful manipulation will enable him to pro- duce with much certainty good pictm'es, for the size of apertoe and time of exposm*e is of no con- sequence, whilst, at the same time, if the manner in which they are lighted and reflected be well arranged and the background judicious; deli- neated by means of Photography they wiU have a beauty of drawing and rotundity which can be Perfection of Jo ^ representa- attained in no other manner. To the tyro in the art, desirous of applying himself to portraiture, some preliminary practice from busts is most desirable, as by such study he desirable for 184 SUBJECTS ; Statues. &o. Proper treat- ment. How lighted. Ant'ques, obstacles to their deli- neation ; stains on them; will gain the power of comparing^ with the greatest exactitude, what the effect of certain apertures of his lens_, distance from the object^ time of expo- sure under different conditions of lights have in rendering the result more or less perfect. The best treatment to adopt for works in marble is^ that they should be executed with a double lens, in moderate light; thus more ro- tundity is obtained^ and the transitions are not too violent_, as they would be liable to become — especially if modem works^ in pure white marble_, were treated in too violent light. Startling effects of sunshine are not for this class of representation; they detract from the delicate modelling of the forms of the originals,, which should be the prin- cipal object to attain^ and in such pictures flat- ness in appearance of the statues or busts is observed. The great works of antiquity offer^ unfortu- nately^ two great obstacles to their being rendered photographically^ which^ could it be perfectly accomplished,, would be most interesting to the world of art. They are for the most part in situations in which the want of light prevents a successful result,, and from which their great value and weight prevents their being temporarily re- moved. Added to which^ the fractures and yellow earthy stains existing on most of them^ make themselves disagreeably conspicuous ; and though THEIR NATURE AND TREATMENT. 185 there is a remedy for this in the very lightest pos- Statues. &c. sible wash of whiting or plaster and water^ skil- lemedy. fully applied^ it is more than doubtful if, in the majority of cases, its application could be per- mitted. Thus we shall probably not see satisfac- tory representations of the Apollo, Laocoon, Venus, &c., unless they should, under very excep- tional circumstances of removal for the restora- tion of the respective galleries, be secured by the local photographers. Such originals are not capable of being repre- sented at very large sizes, for their excellence sizes possible, consisting in the perfection oiform, any distortion would render the picture worthless : one foot is Data for dimension. about the extreme height that the Venus de Medicis could be well rendered, with a six-inch double lens, stopped down to an inch aperture, which would imply excellent condition of light, when a group, as the Toro Farnese (the original of which is in a good light), or the Laocoon, has considerable depth in its composition, their greater dimensions will be photographically neutralized by that condition, and the size limited accordingly. The writer found, in copying the Theseus and Elgin Marbles. Ilyssus from the original marbles, that though they were of heroic size, and offered considerable facilities of lines, it was not possible to exceed one foot in dimension. Busts may be attempted to three and four inches for the head if skilfully treated* 186 SUBJECTS ; Statues, Bassi Uelievi facile. &c. When subjects of this class are executed with Single lens the sinfflc Icus a flatness and want of intensity inefficient. ° result. In modern works of pure white marble^ care must be taken to modify the light by blinds^ other- wise the gradations of half tones^ a principal qua- lity in such subjects_, would be lost in flat white masses void of drawing. Bassi Relievi offer much less difficulty to a perfect result_, from the shallowness of their depth for focus_, and if judiciously lighted the appear- ance of reality with which they can be rendered will find admirers who cannot appreciate their other qualities ; indeed_, the imitation of a fracture or of the granular surface of the time-worn marble, seems often to fix the attention more than the general forms of a masterpiece of antiquity ; but in copying such works the business of the photographer is to omit no precaution which shall secure the representation of the outlines of the whole in great perfection, and not force attention to qualities which are in common with a piece of ordinary masonry. Bronzes will require much more light than marbles, the eruga on antiques will produce a more vigorous action than its appearance to the eye denotes, consequent upon the blue colour pre- sent in it : those of the cinque-cento period, that have an even black dusty character, present greater Common- place quali- ties to be avoided. Bronzes ; their nature. THEIR NATURE AND TREATMENT. 187 facilities ; abstain from touching them as every s tatues, & c. finger mark will appear on the photograph. The most usual failure in representations ofoppSto^ bronzes is the direct opposite of that which takes place with marbles ; in the one case flat white sur- faces appear void of drawing ; in the photographs from bronzes black patches^ without forms delinea- ted on the proofs from bare glass on the negative are more usual — this must be guarded against by a considerable reflexion of light from white — not polished — surfaces_, on the shadow side of the bronzes^ and by sufficient illumination and ex- Remedies, posure. STILL-LIFE. Pictures from objects which come under the still-Liee. above denomination_, are admirably calculated for . 1 • T Desirable for representation by the camera^ and have besides representa- the great advantage of making the student per- fectly acquainted with the peculiar qualities possessed by various textures^ surfaces_, and colours^ and the treatment which each neces- and study, sitates to arrive at a satisfactory result. The most difficult objects to delineate are all bright and polished surfaces^ which reflect white Bright sur- light (see p. 12)^ as armour^ fish^ &c. The most advantageous^ are those whose textures ofPer great 188 SUBJECTS ; Still-Lipe. Varied tex- tui’es. Eeflexion of light. Excellent practice. Desirable quahties. Lenses, light, and aper- tures. opportunities for exact imitation_, such as animals and birds_, carved wood^ mattings_, &c. In making these studies^ it will ' continually be experienced that objects which are of the darkest local colour^ will come out light_, provided that the structure of their surfaces is such as to present portions to advantageous reflexion of light; thus smooth black morocco-leather tells as a dark, whilst the corrugated comes out light. This is a main feature in the action of light on all objects^ and governs their appearance in the photographic picture so completely that the student will find the greatest assistance in his subsequent com- positions_, from the knowledge he will acquire in arranging and photographing groups of still- life. Whilst^ at the same time^ such subjects can be made extremely interesting and picturesque^ and^ from the imitative power of the lens, will always be looked upon with interest, more or less according as the taste of the composition and grouping is artistic and pleasing by contrast of textures, judicious composition of lines, and agree- able light and shade. These subjects may be indifiPerently treated with the double and single lens, and Vv^ith both in a full sunlight, or in shade ; and on these points much experience and knowledge will be acquired by such practice. Small apertures are desirable, since with them the imitation is more complete. THEIE NATURE AND TREATMENT. 189 COPYING PICTUEES, BEAWINGS, PEINTS, &c. AlthoDgli ail objects of still-life present fewer cofYiNo . difficulties^ artistic and mecbanicai^ than figures_, landscape_, &c. ; taking a really good copy from on paintings •1 • • ^ T m T n 1 ' difficult. an oil picture is amongst the most difficult of tnis class of manipulations^ from several causes. The effect of the colours^ as seen in the picture, Colours may probably be transposed in the photograph, and thus a light yellow drapery in the high light of the composition, and a deep blue in the dark portion will, in the photographic copy, produce precisely opposite effects from those which they did in the original. If a highly impastoed surfaces ex- picture, the accidental thicknesses of the colours, drag of the brush, &c., show more conspicuously as textures in the copy, than even the gradations of light and shade of the painting, whilst in- equalities of surface in panels, will attract more attention than the subject itself. Lastly, pictures by the old masters, or those more recent, when covered with yellow varnish, will refuse to come Yeiiow var- out” with any degree of spirit and brilliancy, but remain clouded, obscure, and muddy. The var- nished surface is so much exposed to receive reflexions, from any surrounding objects, that, if Reflexions, great care be not taken to guard against them. 190 subjects; COI-YING. Good quali- ties. Double lens ; its power in definition ; superior to single. Diameter of aperture. Quality of light. Precautions the subject^ in such parts^ becomes obliterated in a sheen of light. Stillj when really successful^ a good photo- graphic transcript from a picture has the greatest interest, as being the actual touch of the painter in little.^^ The double combination lens is far preferable to copy oil-paintings, as it will translate the various tones better, give superior definition, and has a power of greater penetration into all deep glazings, obscure parts, and difficult colours of the original than the single lens. A long-focused lens is the proper instrument ; it has the advantages of giving a larger size, has a flatter field, and — on one line of focuSj which is shallow,— its definition is very superior. These qualities enable it to be used at a larger aperture than a short-focused lens of the same diameter, and render it par- ticularly adapted for this purpose. With a five inch diameter of lens, and one inch aperture, twenty by fourteen inch size may be readily obtained. The light, if out of sunshine, must be very good in order that the most obscure parts of the subject may be perfectly illuminated. Pictures are better copied in the open air, sheltered from the wind, and firmly attached, to prevent vibration. The greatest care must be taken to prevent the direct vertical action of light by projecting a blind above the picture, for one foot or so, other- THEIR NATURE AND TREATMENT. 191 wise tlie inequalities before mentioned will be copying. very apparent. Reilexions from the around and against re- • . . * . rtexions. surrounding objeets must be shut out^ for wliieb purpose an exeellent plan is^ that from the lens to the pieture^ both underneath and at the sides^ black unglazed calico^ cloth^ or cotton velvet;, should be extended over cords^ so as entirely to mask all other surfaces. Fig. 55. The time of exposure given should be consider- able, therefore extra precautions will be required against fogging. Large sized pictures present the Large pic- greatest facilities, the extent of their surfaces radiating more light to the lens, and the reduction 192 SUBJECTS ; Copying . Small dimeii- SIOUS. Quality ot collodion. Chalk draw- ings and; prints. Requisite ar- rangements. which takes place giving better qualities of defini- tion ; but from highly finished works of small dimension, very exquisite copies have been re- cently exhibited which prove the capabilities of photography in this direction. The collodion employed should be in medium condition,, not so sensitive as that required for photography from the life,, which under the lengthened exposure would be sure to fog,, nor in the highly coloured state which is better for copying prints ; as it would then neglect the difficult and obscure radiations. For those who copy pictures profes- sionally a lens specially constructed of the quality before mentioned is very desirable. Prints and drawings in chalks are amongst the easiest class of objects to copy photographically^ unless the texture or colour of the paper should offer impediments^ there are not many points to consider. The print or drawing must be placed exactly square with the lens, that the copy may be free from distortion. The collodion to be employed is such as would be of a bad quality for portraiture, and for this particular purpose has the advantage of preserving the chalk granulations and thin lines in etchings, &c., bare glass, and giving a vigorous deposit on the blank portions; a highly coloured collodion will answer best, the double lens stopped down to the smallest aperture that will give a picture will be the condition requisite, THEIR NATURE AND TREATMENT. 193 as extreme definition is indispensifile^ and if the coptixg. original is on white paper lialf an incli to a four and a half inch lens will, in good light, give a fine result. The point to aim at is that the lines and markings Distinct image. shall he as clear as possible, black lines must he bare glass ; the treatment given in page 109, line 6 et sequitur, gives excellent results if skilfully managed, in developing this class of subjects. Copies from mezzotints require such a quality Mezzot-mts. of collodion as would he used for portraiture, their flat and tender half tones requiring more dis- crimination than other engravings. TTater colour Watercolour drawings. drawings are not easy to copy, the colours some- times interfering, as blue skies, yellow and red dresses, &c., and if executed on very coarse paper the grain shows disagreeably, hut they are infinitely more susceptible of a successful result than oil pictures. As large white surfaces occur in these subjects, the film must be laid very flatly, free from waviness, reticulations and all blemishes, which would show more on a blank white portion than in a subject. Should the amateur, desiring to make a copy from an engraving, not be in pos- session of large sizes of double lenses, it will be Lenses and T diaphragms. better to place the print m direct sunshine, and use the smallest diaphragm possible with the respective size of single lens ; very good copies may be taken thus, but they will not equal those by a long focus double lens. 13 194 SUBJECTS ; Pac-similks. Difficulties. Mode of treatment. Valuable ap- plication. FAC SIMILES OE MANUSCRIPTS, EARLY PRINTED BOOKS, &c. Some of the above offer considerable difficulties to photographic representation, the most in- tractable being those on vellum, the surface of which offers fewer facilities to the reflexion of light than paper, as is perfectly shown by the examination of both under the microscope. The yellow tinge, given by age and discolora- tion, of very early examples, are the great hindrances to successful representation, but much may be accomplished by the skilful use of the double lens stopped down, lengthened exposures and abundant illumination. This is a very valuable application of the art, as by its means amateurs may from distant libraries produce fac similes of unique manuscripts, and portions of rare books. THEIR NATURE AND TREATMENT. 195 STEREOSCOPIC PICTURES. The appearance of actual relief imparted to the steubo- A SCOPICS. photographic image by simultaneously viewing two pictures taken from different points of sight_, is so familiar^ that we will pass at once to the description of the modes of treatment varying with Different modes of different reij^uirements ; presuming that every one treatment, must be sufficiently acquainted with the finished results^ and the manner in which the pictures are inspected. The vexed question of this manipulation is the Theories on exact distance which should separate the two lenses in taking the picture^ and a vast amount of discussion has taken place on this point. Now the real fact is_, that like many other matters connected with Photography^ there is a limit at which scientific theorem must give place to artistic judgment and practice, if the result is to be a picture on the qualities of which, as satisfying the cultivated eye, the propriety or otherwise of Practical results. the whole arrangement depends ; and if that is disagreeable or inefficient, all the abstract disqui- sitions possible on this or the other angle will not make it pleasing or correct. For our Generairuies. guidance in the mean time, there is one very simple general rule, which is, that the nearer the 196 SUBJECTS ; Stekeo- SCOPICS. Sliort dis- tances. Exaggerated angles. Angle varies considerably lenses are placed to the objects to be taken^ tbe less distance they should be separated from each other; that is to say^ at ten feet from the subject three inches apart would be ample to give a natural and at the same time striking relief. The consequences of giving more^ say six or eight inches^ would be — first_, that it would only be after a considerable interval^ and with pain to the eyes of the beholder^ that the two pictures would combine at all ; and^ secondly^ when they had combined^ all the projecting portions of the sub- ject would be in the most exaggerated relief; the nose of the sitter of portentous length ; if sitting, his femur of Brobdignagdian proportion; the arm of the chair some ten feet long, for the accommodation of an equally preposterous human limb, &c. Now this is an error which operators have often committed, probably to astonish the ignorant by an appearance of extravagant relief. The fact is, that according to the class of objects to be treated, the mode of representing them must be varied ; for if such an angle as three inches were applied to a view in nature, the extreme distance being mountains, some ten miles or more from the cameras, the picture would be flat, owing to the insufficient angle given. For such subjects fifty feet apart is not too much, provided always that the foreground objects are not near the lenses, as then they would of course THEIR NATURE AND TREATMENT. 197 Steeeo- SCOPICS. suffer mucli distortion. Sucli would be the two extremes — one tlie nearest approach to an object, the other the furthest removed. All intermediate distances must be managed accordingly, remem- bering only that in treating a subject a certain balance of distance from the camera should be subject, sought for in the picture, which will make the action of the lenses as homogeneous on the near as on the more distant objects, and that when, as in vicAvs in cities, &c., the photographer, from the # restricted nature of the locality, cannot retire his cameras as far from the foreground objects as he would wish, it is much safer to give too little than too much angle ; since in the one case there and locality. Avill only result a certain flatness in the extremely distant objects, those of the middle distance and foreground being Avell represented ; whereas, if in such subjects too much angle is given, the distor- tion of the foreground will be so great as entii’ely to interfere with the success of the picture. There are several Avays of taking stereoscopic A^arious ma- 1 1 • 1 T nipulatioua. pictures, each ot Avhich oiiers certain advantages, and some are more particularly adapted to the objects proposed to be represented. First, then, for pictures from the life, or of an instantaneous nature : these will require two lenses, Avhich must be simultaneouslg exposed and shnutanrous pictiues. covered, in order that expressions and effects may 198 subjects; Stkrro- SCOPICS. One camera. Two cameras Elaborate subjects, be identical in both pictures. They may be mounted in one camera^ in which case the degree of angle is limited_, but the advantage is obtained of operating on one glass plate, and thus securing precisely the same development_, &c._, in both pictures, and affording greater facility of manipu- lation to the amateur. Or they may be mounted Fig. 56. in two small cameras, the difference being that, for distant ol)jects, the angle may be increased at which the picture is taken, but separate plates are required. When expensive arrangements and troublesome compositions of several figures are undertaken, it becomes very desirable that the operator should, at one exposure, secure more than a pair of nega- tives ; in which case, instead of two lenses, four can be used in each of two larger cameras, the THEIR NATURE AND TREATMENT. 199 distance from centre to centre of tlie lenses_, verti- stekeo- T -IT - n T . • -1 -1 SCOPICS. cally and horizontally^ being three inches and a Fig. 57. half ; thus at each time of arranging the group four pairs at once. four pairs of negatives will be obtained. It is better to allow a margin for thickened fringes_, Precautions. stains_, &c._, and take them on glasses eight inches square ; the additional security amply repays the extra expense. With the first mode^ two lenses in one camera^ one glass plate and bath suffices. When the synall Treatment in ^ exciting. plates are used in difi’erent cameras they may be also exeited in one bath by using a glass dipper of four inches in breadth^ which will take both side by side. But in this ease the operator must^ partieularly in hot weather^ be rapid_, or the first covered glass^ having to wait for the other^ 200 subjects; Stereo- bccomes insensitivc. The writer prefers two baths_, SCOPICS. Two baths plate first dipped is thej^r^if put into its preferable, glitle the time becomes about the same for both. Double combination lenses are proper for this k^ses^^’^ purpose^ the diameters an inch and a half and an inch and three quarters; they should be ordered without rack and pinion_, which are useless and add to the expense^ the movement on the bodies of the cameras sufficing. For land- scape many operators use the single lens^ but the double_, stopped down, gives much better stereo- scopic qualities in some subjects^ both of land- scape and vicAvs in cities. Larger beads. Wlien_, instead of gvoups of figures_, heads of some size (about an inch) are intended_, it is more desirable to employ two three inch lenses than to force the one and half stereoscopic ones by approaching too near the sitter with them^ which is sure to give distortion and weak qualities. Lengthened Subiccts treated by more lengthened exposures exposures. ^ ./ o i. can be manipulated in a variety of ways_, one lens and camera — with a sliding back — will give a pair of negatives side by side at any angle which the operator considers judicious. If a near one^ from still life,, Latimer Clarkes arrangement of sliding laths is excellent,, but at considerable angles this is useless. Have two boards, each with dowels/’ corresponding to holes, in the bottom of the camera, screw each board firmly on THEIR NATURE AND TREATMENT. 201 two camera stands — which are necessary — focus the steeeo- subject correctly from both; having taken the picture from one^ cover the lens^ shift the back^ stands, plaee the camera on the other boards and take the other picture. The writer has even used this ^odus from the life ; three to five seconds will put the camera again to work at the second picture. A. better arrangement with sueh subjeets is that the camera should have two lenses^ one over the other. Fig. 58. the advantage being that a square plate of two Four subjects on one plate. pairs IS obtained on the same glass. As has been said, the operator can^ if quiek in his movements, apply this to the life, but for those subjects the simultaneous action is decidedly preferable. The ground glass should be centred with diagonal pencil lines opposite each lens, and when foeusing 202 SUBJECTS ; sterko- observe that the suhiect occupies the same posi- SCOPICS. tion in each compartment. I’orm for The compositions of groups must necessarily be groups. . 01 an upright shape to meet the requu’ements of the stereoscopic form of picture; the artist should endeavour to arrange the subject so as to take the greatest advantage possible of varying Planes of plaues of distance, which will increase the illusion in the picture; consequently it is desirable to Small aper- diminish aperture as much as can judiciously be tures desir- accomplished according to lights &c._, in order that the greatest possible perfection of focus may be obtained on the different objects ; moreover_, the image itself is more rotund and stereoscopic taken at small than at larger apertures. (See page 29.) Manipulation The manipulation with two plates requires some little practice, in order that both may be treated identically, and with the requisite celerity ; the mode of proceeding is as follows, described, Both the glasses should be perfectly ready, lay the film on the first, put it in the bath and cover it ; proceed the same with the second ; after the proper delay, taking the first from the bath, drain Mode of it, and put it in the slide, stand it vertically ; uncovering. t • n i , treat the second in the same manner, and at once expose both. Caps^^ must on no account be attempted with so many lenses, or even with more than one; a double black cloth, carefully THEIR NATURE AND TREATMENT. 203 managed — to prevent the access of diffused light stkeeo- SCOPICS. — answers very well. Eeturning to the operating room_, manipulate the film first excited^ before the other ; develops Mode of developing, smartly as the size is small_, and time is valuahle^, wash the plate well^ and put it down. Proceed with the second^ and endeavour to make both of an equal strength ; should the second he slightly insensitive, drops of hath in the developer will raise it to the power of the first ; wash well^ and proceed to fix both in hypo. and fixing. INTERIORS OF EDIFICES, &c. The most necessary conditions to success in Necessary ^ conditions. these subjects are the quality of illumination which they possess ; and the power, by their dimensions, of sufficiently withdrawing the camera to prevent distortion in the nearer portion of the picture. It is by no means absolutely necessary that the subjects should be lighted from the top, although when that condition is found in picture and sculp- ture galleries, &c., it is more advantageous; win- dows, of some size, in the sides of apartments, churches, galleries, halls, &c., perfectly suffice. One desirable condition is space to retire the 204 SUBJECTS : iNTEKinnS. Cathedrals. Lenses pro- per. Bimension of pictures. Barta for exposure. Lexises and collodion. camera. In cathedrals^ with stained glass win- dows^ or a very dark local colour in the stone,, success will he doubtful,, the operator will find the greatest possible difiPerence in the action in those parts of the building opposite the direct influence of the sun and those in a contrary extreme. Double lenses are alone to be used for such subjects,, three inch short focused lenses with two inch aperture^ will give pictures in twenty seconds to three minutes^ according to peculiarities of light, &c., in the subject ; when the size of the building and conditions of light permit, pictures with ex- cellent qualities can be obtained up to twelve inches square. The writer photographed the sculp- ture galleries in the British Museum — some side- lighted — on twelve by ten inch plates, in two and a half to three minutes, with a four and a half double Boss. In Westminster Abbey, the light being un- favourable it was more difficult to obtain good results, five to ten minutes exposure was required by some objects in north aspects, whilst with those facing the south one minute sufficed. The collodion and the bath should be as for por- traiture, the lenses three inch, six inch focus — three inch, ten inch focus — four and a half inch, fifteen inch focus — will give pictures in the ratio of size of one, one and a half, and two. Thus — six inches, nine inches, and one foot; with corresponding facilities of all kinds to the smaller dimensions. THEIR NATURE AND TREATMENT. 205 ASTEONOMICAL PHOTOGEAPHY. A great deal of special study and treatment_, and AsTEoyoMY. the use of large and perfect astronomical instru- ments^ is required when photographic representa- tions of the moon^ planets_, stars^ &c.;, are attempted_, Lunar and stellar. and success will only he the result of patient and untiring perseverance through discouraging failures. The time of exposure must he prolonged^ and Prolonged the motion of the earth carefully neutralized hy appropriate mechanism skilfully applied. The difficulties of solar representations lie in soiar, its IT- T , T ' n difficulties. another direction ; the heat at the precise jocus, and overpowering intensity of the light_, are the conditions to he antagonized^ which may he accomplished hy sifting the light through a hath of alum and distilled water^ enclosed between parallel surfaces of glass^ which will stop the heating principle, and various tones of grey and green glasses will obstruct so much of the super- Means of abundant light as may enable the operator to obtain a satisfactory image by the most instan- taneous exposure. The best instrument to use for this purpose is a single lens of very long focus, which need not be of large diameter; if mounted in a tube^ and 206 SUBJECTS ; Astronomy, passcd tliTougli an orificc^ the image can be focused on an opaque surface, in a darkened room, and the tube beinff capped^^ from the Exposure in- " stantatieous. lowcr cud ; ou thc film bciug placed in position, it can be exposed with much facility. An image is thus procurable with good qualities of one inch or more in diameter, and capable of enlargement. MICROSCOPIC SUBJECTS. Micro. The application of photography to the delinea- ^ tion 01 microscopical representations ot o meets difficulties. ^Qes not oficr so many difliculties as astronomical subjects; very satisfactory pictures were produced some years since, and more recently several operators, who have given their attention to micro- photography, have exhibited interesting and in- structive specimens of its powers. Objects The class of objects treated have always been mounted transparently thosc mountcd transparently ; amongst those which have given the most successful images are Acari, the tracheae, spiracles, probosci, and other portions of insects ; blood- disks, sections of teeth, bone, and woods, snow- crystals, the appearances produced by polarized light; and recently some describet’^’^® Very successful pictures were exhibited, by a French operator, of Naviculae and Diatomaceae, THEIR NATURE AND TREATMENT. 207 witli remarkable qualities of defiDition and sepa- miceo- . . T . SCOPICS, ration of the markings^ considering tbe size at wbich they had been attempted. The only portion of the microscope that it is object glass ^ of the micro- necessary to use^ is the object glass, which is scope, better screwed into a camera front having a flange adapted to it^ than retained in the microscope body ; thus avoidings by the increased distance of the lateral surfaces^ the chances of reflexions. So that any photographer desirous of giving his attention to microscopic pictures only requires to purchase one or two object glasses^ according to the class of subjects he is about to delineate. The obiect glass of the microscope is of course not corrected for chemical action; but this is of no moment^ since^ after the second picture^ any operator with a moderate degree of skill will be able to fix the point of maximum actinism in which the film should be placed. The difficulties of defective definition increase as the higher mag- nifying powers are used; nor can it be otherwise^ since when these very powers are used optically the fine adjustment screw of the microscope is Qualities of ^ ^ ^ " high required to be kept moving, in order that thero«’«^^” LINE of perfect focus may pass seriatim over the forms inspected. Now, as the photographic picture must be simultaneous in its action, it is evident that perfect delineations of the entire object can only be obtained by the use of mode- 208 SUBJECTS. Micro- SCOPIOS. Size of camera. Nature of light. Exposure. rate sizes^ one incli^ and half inch^ are desirable for the most general and useful representations. The length of the camera body requires to he about two feet. The nature of light used may be varied ; the direct sun-ray received upon clean ground glass or on a bluey white (not yellowy) tissue paper^ is the most desirable illumination. Camphine^ and the Oxy-hydrogen^ light have been employed by very successful manipulators in this department^ in the absence of sunlight. The time necessary to produce the image varies considerably^, according to the nature of light used^ those from artificial sources requiring much the longest exposures ; but the first trial will make a skilful 'photographer master of this portion of the requirements of the lens. It is better to use the direct sun rays modified_, as above mentioned^ than to work by diffused day- light^, since the chemical and visual foci are subject to more frequent derangement^ by dis- persion of light from clouds^ kc., in the latter case. PAET V. PRINTING PROCESSES. In order that the print resulting from the pre- printing. vious labours of the photographer may be satis- factory it is necessary that his care and attention Great care required. should still be maintained and extended to the printing from the negative^ since if it is carelessly or unskilfully executed not only is the permanence of the resulting prints or positive,, jeopardized^ but its very appearance is most inferior^ and totally different to what it would have been had proper Resiuts of skiU and pains been bestowed on its production, negligence, so much so, that it might be difficult for a bystander to believe that two pictures, differing so completely in their quality, could have been produced from the same negative. This is unfortunate, since the consequence is photographs that the photograph cannot be distributed to the in price, public at those moderate prices which would pro- 14 210 FEINTING PROCESSES. Printing. Quality of permanence. Cansons. Desirable qualities. Selection. Points to observe. duce a very general circulation^ and that too often from neglect or the parsimonious nse of expensive chemicals the photograph is deficient in perma- nence^ and a general hesitation and doubts of its powers of duration is created. The impression of the writer is that if all the printing processes are properly and carefully con- ducted the photograph_, with moderate precau- tions against atmospheric infiuences^ is entirely capable of perfect preservation. PAPER, The paper which the writer has found to possess the best qualities is that marked ^^Canson Freres/^ its soft and porous texture seems favorable to the preliminary preparations^ whilst in the toning processes the desirable cool colours are obtained with greater facility on its ^^arcA-prepared surface than on those of the papers sized with gelatine. It is well to give some attention to selection in the purchase of it_, as the large demand seems to have had the efiect of rendering the samples very unequal in quality. Great evenness of texture^ when held up to the lights and absence of small holes^ and of iron spots (arising from the tri- turation of buttons^ ringSj &c.^ in its manufacture) ^are what it is principally desirable to observe. PRINTING PROCESSES. 211 ALBUMENIZED PAPEB. The advantages to be derived from the use of printing. paper prepared in this manner are three. First. Advanta- it has been shown by experiment^ that with the same printing solutions_, proofs on albumenized paper are more permanent ; secondly^ they are more intense and transparent in the shadows of the picture; and lastly^ they possess more delicate definition than prints from the same negative on plain salted paper. To PREPARE THE ALBUMEN. The degree ofModeofpre- paring. gloss to be imparted to the surface of the paper depends mainly on the quantity of water used with the albumen ; the less is employed_, even to the quantity only absolutely necessary to liquidize the salt^ the higher the glaze which will result on the paper. For such^ this formula will be proper : Whites of eggs 100 Recipe for Saturated solution of common salt in distilled 1 , ^ ^ , albumen. y 10 fluid oz. water . , . , . . , J Acetic acid . . . . . .100 minims. This will give a very glossy surface^ desirable for stereoscopic subjects_, and those with much nicety of detail ; the acetic acid tends to preserve the colour of the whites in the prints^ and like- wise to prevent the albumen from turning yellow 212 PRINTING PROCESSES. PaiJfTiifG. Precautions. Better when not freshly prepared. Requisite temperature. with time. If it is desired to reduce the strength of the solution^ to the same quantities add ten ounces, or if more still, twenty ounces, of distilled water. The manner in which the eggs are treated is as follows : break them one by one into a tea-cup, retaining the yelk entire in the half shell, by doing so an accident of contaminating the whole quan- tity with a broken yelk is avoided. As good a vessel as may he for the purpose is a Wedgewood foot-bath ; put the ingredients into it, take a yjooden whisk (sold by brush-makers), well rinced and dried, and beat up the whole, for an hour or so, until it is a stiff froth, which should rise to the height of the vessel ; cover it carefully over, and in about twelve hours decant off the upper clear parts from the dregs ; it may, at any subse- quent time, when turbid, he passed through a fine muslin folded double — which, however, must have first been rinced in common, afterwards in dis- tilled, water. It is in better order for use after it has been prepared a week or two, and has become acid, than at first. The paper must he examined sheet by sheet, held sideways to the light, and the wrong side — distinguished by the square Avire mark — placed uppermost. The manipulation requires care and some skill ; no good result will he obtained if the temperature is low ; it should be 70° to 80°, cer- tainly not less than 65°, — beginners should not attempt large surfaces at first. PRINTING PROCESSES. 213 Pour out^ an hour or so before usings an inch P eintijso. deep of the albumen into a Wedgewood disb, remove any scum_, &e._, with clean blotting paper^ and cover it over from dust — take tbe paper by tbe two diagonal corners^ bring tbe bands together^ and place it on tbe albumen^ wbicb should strike a line across between the other corners ; now^ with Manipuia- tion. a slightly jogging motion_, lower it^ until it floats flatly and without any air-bubbles^ — let it remain 'precisely tivo minutes^ take it up by one corner_, gradually, — ^bold it a minute to drain^ and pin it by two corners on a clean clothes-horse to dry. When dry^ it will be stiffly curled up. The best way to flatten it is to iron with a cool iron^ between sheets of clean blotting-paper. It will require care in keeping, in a dry place, the salt it contains having a tendency to attract moisture. With this precaution, it will keep as long a time as desired. Apart from unskilfal manipulation, attempting Biemisiies. this process in winter, or with a low temperature, causes most of the failures by streaks, &c., as then the albumen will not flow ; even the opening of a door, and allowing entrance to a draught of cold air, will imifnediately show its deteriorating effects. If well manipulated, the surface should be as even and glossy as a piece of satin. Albumen. — This substance is contained in the its nature, blood; the whites of eggs consist entirely of it, and from the latter the photographer obtains the 214 PRINTING PROCESSES. Peintiwg. Uses in plio- togiaphy. Beneficial, and how. Its mode of preparation. Avoiding: air-hulbles. supply necessary. Natural albumen exposed to heat solidifies or coagulates. It is used in several ways in photography ; as a film^ alone_, or in combination with collodion_, to receive the iodide of silver, and in the printing process it is spread out on the surface of the paper, by masking the irregularities of which, it presents more facility to delicate definition, whilst at the same time, by defending the proofs from the action of the atmosphere, it contributes largely to their permanence. PLAIN SALTED PAPER. Should the photographer wish proofs for colour- ing, or to see the different effects produced in certain subjects by printing them on plain salted paper, the manner of preparing it is as follows : — The right side of paper to be carefully selected as before ; a solution to be prepared of — Muriate of ammonia . . 20 grains. Distilled water ... 1 ounce. Let this solution stand about one inch deep in a Wedgewood tray, and float the paper upon it pre- cisely as directed for albumenizing, observing equal precautions to prevent air-bubbles, which would be blank spots on the finished proof. It may re- main three or four minutes on the solution, and then be pinned up to dry. PRINTING PROCESSES. 215 TO EXCITE THE PAPERS. If thick papers are used to print the proofs upon^ the photographer must he careful that the printing. exciting solution is of eighty grains of nitrate of silver to the ounce of distilled water ; other- wise the prints will he weak in the depths. With the usual Canson positive paper, sixty grains suffice; hut the paper is better floated for five minutes than for a shorter period, and Time of floating. the solution must he kept up to the original strength. The exciting solution should he kept in a dark Kept in tha place; and when much discoloured, it may he cleared hy shaking it up with kaolin, which is Purified kaolin. kept hy the vendors of photographic apparatus. The student is cautioned against the use of animal charcoal, sometimes recommended for this pur- pose, as it communicates a solvent quality to the nitrate solution, which dissolves the greater part Result of of the albumen from the surface of the prepared charcoal” ^ paper, thus totally unfitting it for use. A slight degree of discolouration is of no consequence, as the fixing hypo. sol. subsequently removes it entirely. A glass tray or dish is the only proper vessel for vessel this solution, which should he three quarters Qf Printing. Manipula- tion. Precautions. Mode of keeping. State of negative. 216 PRINTING PROCESSES. an inch deep in it. The papers are to be floated as before directed^ and with the same precautions against bubbles. The sheets should be removed with horn tongs kept specially and apart for the purpose. They should be held over the dish for near a minute to drain ; as_, if immediately pinned up to dry^ a long streak of stain will drain from the pin^ its brass having been acted upon by the abundant moisture. Care must be taken that no streams or drops of solution get on the wrong side of the paper^ in preparing it ; as they will cause stains of increased action in the finished proof. As soon as dried, the excited papers should be put away from atmos- pheric influences in a close drawer ; and the sooner they are used the more silvery the tone of colour obtained will be. TO PRINT FROM THE NEGATIVE. The negative having been carefully varnished, and some twelve hours allowed to elapse, in order that any thickened fringes may be quite har- dened, the next process is to print it. The ex- cited paper will require strictly keeping from light and air, especially in hot weather, when even a few hours suffice to decompose its surface ; there- fore, when the best results are desired, it is indeed. PRINTING PROCESSES. 217 better that the paper should be excited only when Pjunting. going to be immediately used_, dried before a and paper, moderate fire^ printed at once^ and toned as soon as possible afterwards. The photograph will have infinitely purer whites^ more brilliant darks^ and is less liable to part with_, or alter^ its half tints^ in the process of toning. The printing presses^, or pressure frames^ are made of various patterns. See that no particles of grit or dust remain on the glass^ nor on the back of the negative^ and place the latter in the frame_, the subject side towards the paper ; remark that it has no flue^ &c.^ upon its surface^, place the excited paper evenly upon it^ put in the blotting papers, flannels, or felt — whichever it may be furnished with — and the back, and screw gently and evenly down. Now, according to the quality of negative which and negative, is being printed, the manner in which it should be printed, to secure the best result, depends — if the negative is slightly under-exposed, whereby the darks are a trifle more bare than they should be, and the deposit on the high lights more opaque than could be desired, printing in the sunlight, at a right angle to the position of the sun, will be the best ; for the reason, that the action being StlS' more penetrating than printing in the shade, the direct sunray will, in a greater degree, strike through the opacity of the deposit on the high Printing. according to their quality. Slightly under-e\- posed. Perfect. Injured by sun-printing. 218 PRINTING PROCESSES. liglits_, and tend to give drawing in tliem^ and half tones ; whilst^ at the same time — the action being very rapid — the extreme darks will yield a little in the toning process^ and not being so black as if printed more slowly^ a more agreeable balance will be established in the picture. A negative of this description is capable of giving thirty proofs in a summer’s day, and is the most rapid printer that we know. The print is not the most perfect, its faults are that there is a certain harshness and crudity in it ; the high lights and darks are in too violent opposition, and are wanting in breadth of effect and atmosphere. The next, and the most perfect negative, is more transparent in the high lights of the flesh, and even white linen, when viewed by transmitted light, is not an opaque mass, but has markings and drawing all over it, whilst the gradations of tone from white to black, are beautifully depicted, and full of charm ; extreme blacks, not being fogged, but still drawn into a little by forms and reflex- ions, — such a negative would suffer considerably by being sun-printed ; the effect would be to give it a general muddy appearance, because the delicate tones and high lights, although quite sufficient for judicious treatment, would be struck through too violently, have lost rotundity, sharp- ness, and brilliancy, and the darks not having had time gradually to take their best vigour. PRINTING PROCESSES. 219 would be vapid and weak ; whilst the intermediate printing. tones would have lost their eorrectness of grada- tion^ and have been much deteriorated. This class of negative should be printed in the shade^ lying flat^ upturned to the sky ; it is not nearly so rapid as the former^ six or eight proofs per diem being all that can be had from it in fine printing weather. The next sort of negative is that which is Over-ex- ° posed. fogged, not by having been exposed accidentally to difiused daylight in manipulating^ but by over-exposure in the camera ; we must make this distinction^ because^ in the first case^ the fogging is merely a veil drawn over a very weak image^ and contains no drawing in itself ; whereas^ in the second; the film; although thickened; and ren- dered thereby very obtuse to light — consequently long to print — contains the drawing of the Subject exists in tlie film. of which it is the refleX; and on sufficient printing; its forms will appear; and it will have some good qualities; although it can never have equally correct gradations of tonC; nor be so bright and perfect as the last mentioned. Such negatives are well printed in the sun; remarking only that; as they will require much time to print them; the prolonged exposure to its Danger of direct action on a summer^s day will be apt to sun-p^mfing. generate so much heat between the glasses that the varnish of the negative may adhere to the 220 PrtlNTING PROCESSES. Printing. Mode of printing a defective. Moderating the light on parts. paper_, and_, on the removal of the latter_, the suh- jeet he injured; to avoid which_, in this class of negatives^ it is well to remove them occasionally into the shade for an interval to cool. Such a negative is the slowest to print — one or two in the day being about the limit in line weather. We have now treated of the three classes of negatives which^ with slight modifications^, repre- sent those which are capable of being printed from_, without any touching or doctoring/^ and which consequently are the only ones which any operator who values his art will tolerate ; still it may happen^ that^ from defective conditions of lights &c.^ a subject rare or valuable in itself may not have been so well obtained as could have been wished ; and in order to enable the operator^ without touching upon them, which cannot be allowed under any circumstances, to draw out the forms which exist in the film, without abolishing, from over-printing, those which have been too legibly impressed, the following expedient is given : — Having perfectly clean- Fig. 59. ed the glasses as directed, ’ place the negative in the centre of the press ; take thick mounting-board, and, cutting it by mea- surement thus, the out- PRINTING PROCESSES. 221 side edge fitting the press^ tlie inside tlie nega- printing. tive that is being printed^ the efi’ect will he to keep the latter always in one place — having done this^ take a proof of the suhiect. We will suppose aMetiiodde- portrait in which the hands, face, and white linen are too opaquQ compared with the dress. Now, if printed in the ordinary way, one of two things must occur : either those parts must be white if the dark dress is right ; or the lat- ter must become an uninteresting black mass, if the former are sufficiently printed up. Yet, observe the drawing exists in the film; we only interpose a blind to retard the action of the light, and in no way attempt abortive touchings on the subject. Take this proof, paste it on a sheet of thick mill-hoard, cut out the white parts, and take care that the outside fits to the sinking of the front of the press, and cor- responds exactly with the parts of the subject desired to he advanced; only rather smaller all round, as the light spreads under the thickness of the two glasses. The subject must be strictly printed in the shade. ji/«s^be shade Now, by exercising some judgment, the white parts are allowed to print in advance of the rest as much as is necessary — say one-third or one- half the time necessary for the completion of the subject; then removing the blind, let all go on together. The subsequent printing will entirely 222 PRINTING PROCESSES, Toning. Better than paper screens Appearances to look for.j Precautions until fixed. Toning. obliterate any edge that may have formed; and being open^ will liave more spirit in the darks than a blind of waxed paper cut through in parts and fixed to the back of the negative^ as is some- times practised. The result^ of course^ is not to be compared to a perfect^ photography such as should be the sole aim of the operator : stilly not being touched upoUy it may sometimes be had recourse tOy in order to save a valuable subject. In all these printingSy the depth of tone to look for must be considerably more than is desirable in the finished proof ; whites must be half tintSy and the sitter must appear a mulatto at leasty leaving it to the toning process to reduce these excesses of colour to their proper limits. As the proofs are taken out of the presSy put them quickly away until they are tonedy which is well executed as soon as possible. A large book of clean blotting- paper is good for this purposCy as it preserves them more securely. TONING THE PEOOES. Should it not be convenient to tone the prints immediately on removing them from the pressesy as before mentionedy great care must be taken to keep them from the influences of light and atmos- phere ; the more so if in a hot climatey or during PRINTING PROCESSES. 223 warm weather. Indeed_, in either of these extremes^ tonikg. it will be found more satisfactory to tone and fix Better toned •' ^ _ immediately. the proofs immediately. If this precaution is not taken, a deterioration in the colour of the white portions will infallibly ensue; instead of a pure, silvery quality, they will acquire more or less of a disagreeable foxy hue. Having poured out the Mode of ma- three solutions, and added to the toning one the quantity of chloride of gold described in toning BATH^^ — strictly in the manner there stated, and having stirred and mixed the solution with a glass rod, take one of the prints by^two of its corners, quickly lay it face downwards in the bath, gently press it under the liquid with the horn tongs; now draw it through the solution, and laying it face upwards, examine it minutely, to be secure that it is free from air-bubbles, and that the whole of its surface is wetted ; turn it face down again : proceed with the next ; and so on. If good prints are desired, avoid having too many Few toned at of them toning at once. If they are crowded, or the quantity of liquid is scanty, some are sure to suffer by inequality of tone. They must be con- stantly kept in motion, the more so, even to conti- nuous manipulation, the better the result. Not only do they thereby avoid reddened patches of unequal action, but they tone quicker, part less with their colour in the lighter shades the half- tints, and have more brilliancy and intensity in the 224 PRINTING PROCESSES. Toning, darks. Do not fail to look frequently at the Eiequent advancing tone of colour they are acquiring in exaiuination. _ _ the bathj Trhich Tv^ill be much more rapid as the temperature is higher^ and slower when it is low. Before they are quite as cool in tone as desired, remove them to the second hyposulphite or clear- ing-bath. After they have been in that for five minutes or so, hold them up to drain off super- Fixing baths, fl^ous moisturc, and pass them at once to the fixing bath, in which they may remain from five to ten minutes, according to temperature. Upon the employment of a perfectly clean solution of Necessity of Jiupo for fixing the proofs, their stability, and much a pure hypo bath. of the beauty of their appearance, depends. As its action continues, it will be observed that the light portions, which were yellow in colour, will, as the components of the toning-bath are removed from the texture of the paper, become pure and white ; and on the perfect removal from the paper of those metallic and chemical combinations. Removes the soluble, and capable of entire removal by the clean from the hypo, but which, if left unremoved by it, the mere paper ; water in the next process would have been ineffi- cient to touch, the stability of the finished photo- graph depends, the proof of which is easy, by washing a print direct from the toning-bath and marking andistV5c// the rcsult. The pure hypo is soluble in water; and, wtS® though penetrating in its nature, can be entirely removed, by judicious washing, from the paper. FEINTING PEOCESSES. 225 Tke infinitesimal division of the metallic particles toning. in the toning-bath is great^ their nature and action subtle^ and as yet very imperfectly ascertained. The operator will do well to avoid dipping the iu wash- fingers into this solution^ and to avoid contact by the use of the horn tongs^ as the neglect of this precaution may have unpleasant results. The prints are now to be withdrawn and immediately put into clear cold water^ the softer the quality the better. Too much attention cannot be given to the complete manner in which they are turned, and the waters changed continually, especially at first. It will be evident that if they are allowed at the commencement to remain in a shallow tray, with a small quantity of water, they would in reality only be in a weak solution of hypo, which would be acting upon and deteriorating them. The changing of the water, if a running stream- — which is infinitely better' — cannot be procured, must take place in large earthenware or gutta percha vessels, at something like the following intervals : i hour ; J hour ; 1 hour ; 2 hours ; 4 hours ; 8 hours ; 12 hours. Approximate intervals. Thus changing them, as will be observed, the more often as they have more recently left the hypo solution. At the end of this time, remove them from the water; drain each for a few seconds; then blot them off between sheets of clean blotting- paper ; and either suspend them to thin cords to 15 Fixing. Modes of dryiug. Destructive vessels. 226 PRINTING PROCESSES. dry — for which purpose the wooden American clips are useful_,— or lay them on a sheet. When dry^ either pass a cool iron over the hacks to flatten them ; or^ better^ put them for a night in a press. They are now ready for the mounter. Note_, that more than twenty-four hours in water is entirely useless^ and even detrimental to the prints^ provided that they have been well changed. A continuance of long periods in water^ is sufficient of itself to produce visibly deteriorating effects : also^ that any attempt to wash them in painted or japanned vessels^ or those made of lead^ zinCj or other metals_, will result in the imme- diate destruction of the proofs. PAET VI. SOLUTIONS AND CHEMICALS. THE NITRATE BATH. The most important of all the solutions to the photographer_, is undoubtedly the Nitrate Bath. Its contamination by contact with any organic substances^ or by neglect of any kind_, is so fatal to success^ that the merest tyro in the art soon becomes imbued with profound respect for his bath. But as the reader may not be aware of the precautions which have been found in practice to be necessary to its preservation in the best work- ing order^ the following remarks are offered : — Several formulae have been given by various writers for the preparation of the Nitrate Bath^ some of which are simply an iodized solution of thirty grains of crystals of nitrate of silver to the ounce of w^ater_, whilst others are of a more com- plex character^ and various other ingredients are Nitrate Bath. Importance to the mani- pulation. Various formulae. 228 SOLUTIONS AND CHEMICALS. N ITEATE Bath. The one re- commended. Quantity necessaiy. Quality of chemicals. Bottles, &c., cleansed. used in their preparation. The writer has made ' trial of several^ but has not found in them that stability in a satisfactory condition that the more simple preparation gives. They are very excellent in their first results^ but rapidly deteriorate by use^ even when carefully treated and kept strictly from light ; and he has therefore discontinued the use of all but the one of which the formula is given in this section. In preparing the solution^ the operator must be guided^ as to the quantity necessary, by the sizes that he is likely to execute. If they are at all large, considerable waste of the solution will ensue and have to be provided for ; and it is not judicious merely to have at hand the quantity necessary to fill the bath in ordinary use ; it being better to have twice that quantity prepared. The chemicals which enter into the composition of the Nitrate Bath should be of the most un- doubted purity, which is best attained by purchas- ing them only from vendors of character and respectability, who making it especially their con- cern to procure them for photographic uses, will, by testing and otherwise, insure their quality. In preparing the solution, if the bottles to be used are new, they must be cleaned by having a weak solution of nitric acid and water shaken in them, and afterwards well rinced — first, in com- mon, secondly, in distilled water. The measures. SOLUTIONS AND CHEMICALS. 229 funnels^ spoons^ and glass rods must be scru- niteatk pulously clean, and none of them must bave been ' used with solutions of hyposulphite ; indeed merely putting a stopper down on a table on which hypo had been spilled, and returning it to a bottle would suffice to spoil a bath. The above method of cleansing new bottles applies equally to new glass baths. We now proceed (in a yellow light) to prepare Modeofpre- pai’ation, the solution. The formula is that originally pub- lished by Mr. Thomas ; and the writer has found it to be the one which gives baths of the most even and enduring qualities. It is to be made in the following proportions Into a stoppered bottle put Nitrate of silver ... 1 ounce. Distilled water ... 2 ounces. Dissolve. Into a glass measure put Iodide of potassium . . . 4 grains. Distilled water ... 1 drachm. When dissolved, pour it into the bottle. The precipitate of iodide of silver forms in curdy flakes, which, on well shaking, are entirely dissolved. Now add fourteen ounces of distilled water, when the excess of iodide of silver is again thrown down, but in such a finely divided state as to ren- der the saturation of the bath with iodide of silver 230 SOLUTIONS AND CHEMICALS. Nitkate Bath. and preser- vation. Testing the soUtion. perfect. Allow it to stand half an hour or so; carefully filter; it should then be as bright as distilled water. Afterwards, add Alcohol .... 2 drachms. Sulphuric ether ... 1 drachm. Note^ that the bottle in which it is prepared should be larger by one-third than required for the solution^ in order to give room for shaking it well. When prepared^ it will be best preserved for use in stoppered bottles^ with brown paper pasted over them; which has the double advantage of keeping out light and giving the operator firmer hand-hold with large sizes. The solution should be carefully kept from extremes of temperature. It is better^ thermometer below 40° or above 60° Fahr.^ to return the so- lution into an inside cellar immediately after study. The solution should be scrupulously kept from the action of white lights a mere passing gleam of which suffices to set up an action which will be progressively deteriorating. Before operating, the bath must always be tested for its condition (see page 120), which should, for the life, &c., be just acid. It is well to have more than one bath in use, at different points of acidity ; by using various states of collo- SOLUTIONS AND CHEMICALS. 231 dion in whiclij tlie photograplier can obtain in tbe nitratk . T . BiTH. picture any qualities ne may desire. If operators will use gutta-percba batbs_, tbey Gutta perciia must when new be filled with a strong solution of common soda^ which should remain several days in them_, afterwards rinced^ and a solution of nitric acid and water, which should equally remain some time, then common water, well changed and rinced with distilled before putting the bath into them. With all this precaution, if the solution is left in them it will deteriorate ; the only way is to remove to if used, ne- cessary pre- glass bottles immediately after study, rince out the cautions, gutta-percha with distilled water, and cover it from the action of atmospheric impurities. The writer has just taken pictures with portions of the same bath, which has been left for six months in two baths, one of solid glass, the other of gutta-percha, the results are as follow ; The bath solution was one which had been uata of a bath solution. considerably worked from, previously to its having been put away. Both baths had been preserved in woollen wrappers, and had been kept during the winter months in an inside double doored wine cellar. When tested for acidity, both were found in comparison of glass and the same state, being just acid. The pictures g^ttapeicha. taken with that portion kept in glass showed the best qualities (see p. 113), those taken simulta- neously with the other portion were distinguished 232 SOLUTIONS AND CHEMICALS. Nitkatb Bath. Varied quali- ties. Principal de- rangements. Manner of maintaining quantity. by great insensitiveness to the darker portions of the subject^ the plates were not clean, long streaming marks, very similar to those in fig. 48, (p. 129), appeared all over the subject, which were capable of removal by friction Avhen the film was dry. The difierence of colour by diflPused light was great, the one being a bright yellowy drab^ the other a dull brick red. On printing from them, the latter was found to be insensitive to the delicate gradations of tone, perfectly delineated by the other. Now the writer conceives that any attempt t,o restore such a bath would be useless, the only thing to do would be to condemn it altogether, and that the same condition, in a modified degree — according to lapse of time, — exists more or less in all bath solution kept, or brought in contact with gutta-percha vessels. Apart from contamination by contact with organic substances, and access of light, the prin- cipal derangement of the bath is caused by its being in an improper condition of alkalinity or acidity; before commencing operations, its state should always be ascertained by testing, and if found unsatisfactory, corrected as described at pages 120 and 123. It is always advisable to allow a short time to elapse after pouring it out from bottles, or when it has been shaken about in a van, &c., before operating with it. It is a good plan to replace the waste of the bath caused by SOLUTIONS AND CHEMICALS. 233 Hse^ with 2 l plain solution kept for the purpose^ of nitkateop thirty grains of nitrate of silver to the ounee of ^ distilled water, hy whieh means the hath is kept from being super-iodized by the constant dip of the films (see p. 127). NITRATE OF SILVER. Two varieties of this salt are in general use. nituate of ° _ SlEVEU. The cheaper and most extensively used nitrate is prepared by the refiners from their waste liquors, &c., from which formerly the silver was recovered various qua- lities. by first converting it into chloride ; as met with in the shops, it is in rather small irregular-shaped crystals, having a white effloresced appearance, and being more or less opaque ; it is seldom quite pure. Pure nitrate of silver is made by dissolving pure silver in nitric acid. On evaporating the solution Pure uitmte, " its appear- the salt crystallizes in colourless transparent tables, free from smell of the mother acid ; in which state it is to be had in the best shops. The solution of this salt should be neutral to test-paper. This is the kind which should always be used in the pre- paration of the bath. When nitrate of silver is dissolved in excess of ammonia, the solution should be colourless. As nitrate of silver readily spoils Piecautious 1 . 1 . .1 . for its pre- by exposure to light in contact with organic matter ^ servation. great care should be observed in the keeping of . this salt, a small fragment of cork, or a little 234 SOLUTIONS AND CHEMICALS. Iodide. Treatment of the crystals. Fus -d nitrate. Its mode of preparation. How tested for purity. Specific gra-' vity. lint_, from a cloth_, being capable of spoiling any quantity. Before making batb-solution^ it is proper to place the crystals in a glass dish, and in a cool oven 200° Fahr, stirring them continually with a glass rod; the effect being to drive off any re- mains of the mother acid still adhering to them, which would have retarding qualities. The writer has made several trials of fused nitrate, with skilfully prepared samples, for the bath-solution, but has not found them successful in practice, and would recommend the ordinary crystals in preference. Iodide of Potassium, being prepared by mix- ing carbonate of potash with iodide of iron, fre- quently contains a little of the former salt. When pure, it is in crystals of the form of a cube, and causes no precipitate if dissolved in lime-water. Distilled Water is tested for purity and freedom from contamination by organic matter, by dissolving in it a crystal or two of nitrate of silver; held in bright light it should remain limpid as before, any cloudiness appearing would show it to be unfit for the preparation of the nitrate bath, &c. Alcohol is a limpid, colourless, inflammable liquid, having a peculiar and penetrating odour. Its specific gravity at 60° Fahr. is 0*7947 ; at 68° Fahr. it is 0*792. No means of solidifying it are known. SOLUTIONS AND CHEMICALS. 235 Alcohol has a strong affinity for water ; hence Alc ohol. it abstracts this fluid from the atmosphere. It is Preparation, prepared by the chemist from the rectifled spirit purchased from the rectifier. It is obtained by adding choride of calcium^ carbonate of potash, or well burnt lime, to the spirit which is thus dis- tilled. The salts or lime retain the water whilst the alcohol distils over. In photography, alcohol is used in several solu- its uses, tions ; hut, where required to he of the most absolute pv/rity is in the additions made to the collodion. Should it contain water, the qua- lity of the film will he thereby greatly deteriorated. Sulphuric Ether is prepared by the distilla- tion of rectified spirit and sulphuric acid. It is Mode of “washing.” rectified from water, sulphurous acid, &c., by the addition of carbonate of potash and re-distillation. It is a colourless, limpid fluid, having an agreeable fragrance. The ether of the shops contains a little alcohol, and its specific gravity varies from 0.733 to 0.765. Newly washed for photographic use, its specific gravity at 60°, Eahr. is 0*720 to 0*725, and it should Specific gra- vity. not redden litmus. Pure and recently prepared ether possesses neither acid nor alkaline qualities ; hut by exposure to light and air, it absorbs oxygen, by which acetic acid and water are produced. The ordinary ether of commerce is contami- When con- . . tainingwater, nated with either spirit or water, or both. Caution 236 SOLL'TIOXS AND CHEMICALS. Collodion. Importance in ihe pro- ess. Desirable’ quaJiries. Defects. must be observed in approaching a candle near the nnstoppered bottle^ as its yapour is highly inflammable. Collodion. — Much of the success of the photo- gi’aphic manipulation depends on the nature of the collodion employed ; the qualities most de- sirable for it to possess ai’e, that the film laid from it should be even, and free from all reti- culations_, specks or marks of any kind yrhateyer; that it should flow freely and eyenly, that it should be yery sensitiye to the obscure radiations fr’om the subject; whilst the deposit it giyes on the highest lights should not be of too great opacity ; that it should remain for a considerable period colourless and sensitiye. If in portraiture^ and pictures from the life^ it is insensitiye^ the skill of the operator will not ayail him^ and not only will the expression of the sitter become heayy and nnpleasing, from the time necessary to take the picture^ but the light and shade will be faulty and disagreeable^ and the whole pictm’e unsuccessful. Mhilst in copying chalk drawings^ prints^ and for microscopical and astronomical pm-poses^ if the collodion used is not perfectly structoeless and clean in the film it giyes and the image it pre- sent s^ it will be yalneless for those uses. It is better to purchase it prepared by those whose sole care it is to procure the necessary SOLUTIONS AND CHEMICALS. 237 ingredients of undoubted strength and purity^ and collodion. to give their exclusive care to its preparation. Collodion varies much in its qualities,, according as it may have been more or less recently iodized ; if intended for portraiture^ &c.^ twelve to twenty- four hours is the best time to use it after iodizing ; the qualities' it then possesses are — more sensi- tiveness and less intensity — which latter is advan- tageous^ since in printing from the resulting negative the light permeates through the highest lights, which are thereby full of forms and gra- dations of tone. The same state is proper for interiors, instantaneous pictures, and all subjects difficult by their local colours or illuitiination. Landscapes, architecture, exteriors, stereoscopic ^ ^ ^ ^ ^ For various pictures (being executed with small rapid lenses and requiring extremely clear definition on a diminutive size), still life, statues, &c., will be better treated by collodion in the middle state, which allows longer exposures without fogging, gives greater intensity and clear definition, but necessitates more time than the first. Whilst chalk drawings, prints, maps, fac-similes of MSS., &c., will be advantageously taken with a sample long iodized and insensitive to half tones, but giving bare glass and intense deposit. The operator will find appropriate uses for samples in all stages of iodization, and, if hy the same maker, they may be advantageously com- bined to meet certain requirements, or by having 238 SOLUTIONS AND CHEMICALS. Toning liATH. Different batlis. Precautions. Formula for solution. Mode of pre- paring. two or even three batlis in different states of neutrality, moderate and greater acidity, very ex- cellent pictures will be obtained, since by the skilful and judicious combination of their qualities witb varying states of collodion the operator may so modify bis means as to meet every requirement in the manner the most advantageous to the sub- ject undertaken. Caution is required in not approaching too near lights with unstoppered bottles of collodion, its vapour being almost as inflammable as that of ether. THE TONING BATH. The solution for giving the desired degree of colour to the proofs, is composed in the following proportions. Clean water Hyposulphite of soda Chloride of silver Chloride of gold 10 ounces. 5 ounces. 40 grains. 10 grains. Dissolve the hypo in eight ounces of the water, add the chloride of silver, stir well ; take a clean developing glass, put in it the ten grains of chloride of gold, add the remaining two ounces of water, dissolve, and stir well with a clean glass rod, now keeping the first solution in motion by stirring it briskly, add the second with a sweeping motion, which shall at once intimately mix it with SOLUTIONS AND CHEMICALS. 239 the hypo (not pouring it in one spot). The tonikg sooner it is used the better^ indeed^ the gold should only be added immediately before it is wanted. This solution must be prepared in a deep keeping yellow lights and kept strictly in the dark ; when neWj the above is the formula, afterwards^ the chloride of silver will not be needed^ being supplied from the proofs^ as they are toned in sufficient quantity. When quite freshly prepared^ the tones obtained are not agreeable^ being too gay and purpling in colour^ on further use these will give place to fine deep shades of violet brown^ ap- Desirable 1 . IT ^ colours. proachmg black. There are several conditions which must be carefully noted as affecting this manipulation. Tirst_, the bath must be tested each time before usings and if more than slightly acid_, it must be Tested for corrected with drops of solution of carbonate soda in distilled water — testing between each addition — until nearly neutral; were it in much excess of acidity^ the half tones and delicate markings of the subject would be injured or effaced. Xext_, on the state of temperature depends greatly the time required for toning_, varying from ten min utes^ at 80°_, Fahr._, to two hours at Affected by , temperature. 40°, Fahr. The lighter parts of the subject are better preserved when the time occupied in toning is not 240 SOLUTIONS AND CHEMICALS. Tomxg Bath. E.x:pe(lieiit ft equalizing. Continual changes. Mode of operating. too much prolonged ; therefore^ in cold weather it is well to raise and keep up the temperature of this solution to 60°. Those who print in large numbers would find a • pewter hot water case, communicating with a boiler, on which to place the ATedgewood tray, advan- tageous ; when merely a limited number of proofs are required, the following expedient will be found quite satisfactory. Take a deep Wedgewood tray, a size smaller than the one containing the toning solution, fill it with boiling water, and stand the tray Muth the bath upon it for half an hour before using, the temperatui’e should show an increase of 20° in winter. As has been preTOUsly said, the fiocing bath of hypo gradually becomes a toning bath, by the accumulation of the portions of the latter which it acquires, and thus partially or entirely saturated, it is unfitted for its purpose of clearing the proof from the toning chemicals. The manner which the writer has found very satisfactory to manipulate this part of the process, is as follows : — have three TV edgewood dishes. No. 1. No. 2. No. 3. The The Quite Toning Middle clean Hvpo Bath. Bath. fixing. 1 SOLUTIONS AND CHEMICALS. 241 The proofs having nearly acquired the proper solutions . tone in No. 1^ are passed on to No. 2, Avhen a considerable portion of the yellow colour in the whites is seen to be discharged^ whilst the darks acquire cooler tones ; having remained according to the temperature^ as previously directed^ they are to be passed through water to remove the solution from their surfaces_, and placed in No. 3; here they will be observed to become silvery in the darks and absolutely white. If now they are properly washed^ as elsewhere directed^ they will Permanency, be permanent. Proofs taken direct from No. 1^ washed and dried^ will fade in a few weeks. Proofs passed through No. 2 may last a few months. The writer has not known a proof toned and Vanous qua- litiea. fixed as mentioned^ and subsequently thoroughly washed_, to fade^ although many of them are freely exposed to the gases of a London atmo- sphere. The other advantages of this treatment are^ that . before No. 1 solution becomes stale^ and gives tones deficient in freshness^ it is withdrawn and renovated by the continual additions from No. 2, which^ in its turn^ is improved from No. 3 ; where Benefit of three solu- entirely new and clean hypo is being placed, the tions. intermediate bath prevents the fixing from being so quickly contaminated — thus saving trouble and 16 242 SOLUTIONS AND CHEMICALS. Solutions. Continual addition of gold nece.-i- sary. How pre- pared. Colour of tlie crystals. How best preserved. expense — and at the same time is preparing itself to take the place of the toning. Betn^een each batch of prints_, which should be in small quantities (not more than ten)_, addition of gold to the bath is necessary, in the ratio of two and a half grains to each twelve by ten print. Manipulate strictly, as follows : take one ounce of new saturated sol. hypo, add to No. 1, — into two ounces of water put twenty-five grains of chloride of gold — dissolve. Now, stirring as before directed, put in the gold solution, and tone a surface of prints equivalent to ten of 12*10. The saturated sol. hypo, balances the ivater introduced with the gold, and the weak additions from the other trays. Chloride oe Gold is produced by dissohdng pure gold in nitro-hydrochloric acid. The deep yellow solution thus obtained yields, by evapo- ration, yellow crystals of the double chloride of gold and hydrogen ; when this is cautiously heated, hydrochloric acid is expelled, and the residue, on cooling, solidifies to a red crj^stalline mass of ter- chloride of gold, very deliquescent, and soluble in water, alcohol, and ether. When pure it is of a very deep orange colour; for photographic use it is better purchased in several small well-stoppered bottles, containing each from twenty to twenty- five grains, as, if exposed in larger quantities to the atmosphere, it will become deteriorated by SOLUTIONS AND CHEMICALS. 243 deliquescence^ caused by tbe removal of tbe soLrxioNs. stopper. Chloride of Silver is a cbalky-looking, white powder^ insoluble in water and nitric acid^ but soluble with ease in cyanide of potassium_, bypo- soluble, sulphite of soda_, and ammonia. It is procurable by adding a saturated solution of common salt to a solution of nitrate of silver. It falls as a white^ curdy precipitate_, which^ well washed and dried^ is cliloride of silver. It is decomposed by light both in a dry and wet Decomposed state ; very slowly if pure^ and rapidly if organic matter be present. DEVELOPINO SOLUTION Is prepared in the following proportions : Proportions. Distilled water 1 — 10 — 20 — 40 ounces. Pyrogallic acid 3 — 30 — 60 — 120 grains. Acetic acid ^ — 5 — 10 — 20 drachms. Alcohol — 11 — 2^ — 5 drachms. Mix the distilled water and the pyrogallic acid_, when quite developed filter carefully; 7ioiv add the alcohol and acetic acid. When made in these proportions it keeps better than when prepared of less strength. It is easily diluted as required to meet circumstances of light and temperatm’e. “Three grain” solu- tion. SoLrTio:Ts. Laziit and Ltat icju- rlozis. How ob- xsuntd. Tested. Glacial im- necfcssarv. Useless ex- pense. 244 SOLUTIONS AND CHEMICALS. It sriould be kept from tbe ligbt_, and_, in summer, in a cellar ; in cool weatber it -sYill keep a month or more, in summer a Meek or ten days ; a sbgbt discoloration is of no consequence, but if it passes beyond its poTrer of deueloping slight action on the fihn is impaired. Pykogallic Acid is prepared by heating quickly tannic or gaUic acid, previously well diied ; it is obtained as a sublimate in white plates or needles, possessing a strong empyreumatic odour and bitter taste. It should not redden litmus, and should not be kept in solution. Acetic Acid. — This is seldom really glacial, nor is it, indeed, important for the collodion pro- cess that it should be so. The presence of a very small quantity of water halves the price of the acid, and is not worth consideration. In its most concentrated form it should be solid at 60°, but when of this strength it is very expensive. SOLUTIONS AND CHEMICALS. 245 THE EXCITING SOLUTION FOR PRINTING_, Is composed of soluttons. Nitrate of silver ... 60 grains. DistilLd water ... 1 ounce. If tliick papers are used^ sucli as Papier Saxe^ strength for . , . p • Ml 1 -I • thick papers. eighty grams oi nitrate will be required to give good results. This solution will in process of use become weaker^ and crystals of nitrate must be added to it to keep it up to the requisite strength : it will likewise become discoloured. This, to a certain Mode of dis- coloiuing. extent, does not signify, provided the paper ex- cited with it is used at once, as the hypo fixing bath removes such stains from the whites, and leaves them perfectly pure. When more, however, than a mere light brown discoloration has ensued in the solution, it may be removed by the use of Kaolin,^^ or china clay, which is to be shaken up with the darkened solution, in the proportion of about twenty grains to the ounce of liquid ; and it will precipitate the discoloration. The upper portion may then be decanted. The reader is cautioned against the use of Animal cimr- . 11 1 P 1 • n ’ destruc- animal charcoal for this purpose ; as on floating tive. 246 SOLUTIONS AND CHEMICALS. Solution s, albumenizcd paper in a solution so purified, the albumen detaches itself from the paper, and the result is very damaging to the proofs, which are totally deficient in depth and brilliancy. The horn tongs are to be used in this solution. They keep the hands free from stains and the paper in better condition. Inferior Inferior nitrate of silver is sometimes recom- nitratc. mended, as being cheaper, if ‘‘only required for printing’^ If such is used, the permanency of the proofs will certainly be jeopardized. Pure nitrate of silver should be employed. It is not necessary that it should be re-crystallized, as for the bath solution. FIXING SOLUTION. FOR THE FILM. Saturated The abovc is prepared by saturating any desired solution. quantity of water, according to size of the bath, with hyposulphite of soda ; that is, until the water will dissolve no more. It will become discoloured by use, which is of no consequence : indeed, it is Better when better whcn not perfectly new ; its action is less violent on the delicate parts of the deposit. SOLUTIONS AND CHEMICALS. 247 Fixing Solution (for printing) is prepared in the following proportions : — Filtered water . . . 15 ounces. Hyposulphite of soda . . | lb., Avoirdupois. Hyposulphite of Soda is made by digesting sulphite of soda on flowers of sulphur^ at a high temperature. It occurs in white, transparent crystals, and is very variable in quality. When good, it should dissolve one half of its weight of iodine ; and its solution should give no precipitate with a soluble salt of strontia or lime. Solutions. Mode of pre- paration. Test of goodness. 248 -si .y •S ^ lO r— I tO •9inUI'Bl29niJ\[ 1 10 100 1000 10,00 100,000 1,000,000 •9nmiBjSi')n93 1 10 100 1000 10,000 100,000 •9nna'B.i§i99(j 1 10 100 1000 10,000 •9TniU'BJf) 1 10 100 1000 •9Tnmt3.l2B99(J 1 10 100 •9rainBJ°op9jj : : : : • ' ® •9uiraBa§0{i;a i i : i ! : - 249 WEIGHTS AND MEASURES. TROY WEIGHT. 1 grain. 20 = 1 scruple. 60 = 3=1 drachm. 480 = 24 = 8 = 1 ounce. 5760 = 288 = 96 = 12 = 1 pound. FLUID MEASURE. 1 minim. 60 = 1 fluid drachm. 480 = 8 = 1 fluid ounce. 9600 = 160 = 20 = 1 pint. PARALLEL OE ENGLISH AND FRENCH MEASURES. French litres, 4-5455 = 0-5682 = 0-2841 = 0-0355 = 1-000 — 0-001 ) eentimetre cube J 1 gallon. 1 pint = 20 fluid ounces. 1 fluid ounce. 1 fluid drachm. ^ 0-22 gallon. 0-76 pint. 15-4 grains of water, at 62® Fahr. INDEX. Aberration, spherical, 28 ; chromatic, 35« Accessories, how arranged, 145. Acetic acid, 121. Acidity of bath, 123. Actinism illustrated, 18. ‘^Adapters/’ 69. Albumen, 213. Alcohol, 234. Alkalinity of bath, 120. Amber varnish, 118. Angle of light on sitter, 61. Animal charcoal, 245. Animals, modes of photographing, 180. Animation in portraiture, 146. Architecture olfers, facilities, 173; subjects, 174. Area, in the eye and the camera, 28 ; defects of large, 29 ; of aperture, importance of, 55. Aspect of glass studio, 58. Atmosphere acted .on by light, 37. 252 INDEX. Backgrounds, 143. Bassi-relievi, 186. Baths, glass, advantageous, 86. Bath, nitrate, 238. Blinds for diminishing light, 61. Bottles, various, 90; cleansed, 228. Box, operating, described, 171. Bronzes, 187. Busts, 184. Camera, action compared with the eye, 26; portrait and landscape, described, 69; test for, 70. Camera stands, 73. Chirurgery, photographic delineations of, 183. Cleanliness, chemical, 65. Coincidence of foci, its nature and action, 36. Comets, 127, 128. Collodion, viscous, 124; qualities and defects, 236; mixing, 237. Colour, result of dispersion of light, 13 ; varieties in nega- tives, 113. Colours for walls of studio, 62. Defects, 119. Definition, 44. Developing, stand, 84; glasses, 88; the image, 107. Development, 107. Diaphragms, nature of, 47 ; holder, 49. Dimensions for portraits, 160. Dippers, silver- wire, 82. Distortion, 148. Drawings, copies from chalk, ]92. Ether, sulphuric, 235. Exciting tray, 94; the film, 101. Exposing the film, 103. Exposure, time of, 104. Eye, the, action imitated by the camera, description of, 21 ; piece focusing, 95. INDEX. 253 Eac-similes of manuscripts,, books, &c., 194. Entering papers, 96. Eixing, the negative, 115 ; bath, 224, Eocus, depth of, 41, 45 ; importance in portraiture, 147. ‘‘Eogging,” 109, 120. Eunnels, 88. Glasses, 79 ; mode of cleaning, 80. Gold, chloride of, 242. Graduated glass measures, 88. Groups, in tlie studio, 150 ; radii, 157. Gutta percha, trays, 87 ; mode of cleansing baths, 231. Head rests, 77. Horn tongs, 90. Hyposulphite of soda, 247. Instantaneous pictures, 160 ; subjects for, 161. Intensity of the image, 110, Interiors, 203. Kaolin, 245. Landscapes, 166. Laying the film, 98. Lead acted upon by the chemicals, 66. Lenses, non -coincident, 36 ; coincident in foci, 38 ; various, for different uses, 39 ; dimensions, 40 ; definition of, 41 ; test of qualities, 42 ; slow, how caused, 46 ; double, 56 ; flat in field, 147. Light, sources of, 11 ; reflexion of regular and irregular, 12 ; intensity, 12; refraction of, 14; dispersion, 15; absorption of, 19 ; diffused, 133, 219. Linen cloths, 95. Manipulations, 97. Marine subjects, 178. 254 INDEX. Marks, of drainage, 131 ; of slide, 132. Mezzotints, to copy, 193. Microscopic subjects, 206. Negative, to print from, in direct sun, 218 ; by diffused light, 219. Nitrate bath, 227 ; formula for, 229 ; testing, 230 ; data respecting, 231. Nitrate of silver, 233 ; fused, 234. Operating room described, 64. Over-exposure, 107, 122. Paper, 210 ; albumeuized, 211 ; plain salted, 214 ; to excite, 215. Parallel of the action of the eye and camera, 26. Pathology, subjects relating to, 182. Photography, astronomical, 205. Pictures, copies from, 189 ; stereoscopic, 195 ; various treat- ments, 198. Plate holders, pneumatic. 85. Portraits, 137 ; heads only, 138 ; full-length, 139 ; three- quarter, 139 ; conditions for portraiture, 143. Printing, frames, 93 ; processes, 209. Prints, copies of, ]92. Proofs, permanency of, 241. Rapidity of lens, 138. Rays, visual, not photogenic, 19 ; oblique and parallel, 37- Reflectors, various, 149, 153. Reflexion, 133, 188; to guard against, 191. Retort stand, 89. Rustic figures, mode of treating, 157. Seale for apertures, 56. Scales, 83. Silver, deficient in film, 134; chloride of, 243. INDEX. 255 Sketches recommended, 141. Solutions, for plain salted paper, 214 ; toning, 238 ; developing, 243 ; exciting, 245 ; fixing (for the film), 246 ; fixing (for printing), 247. Specific-gravity bottle, 85. Spectrum, solar, its nature, 15, 19. Spirit lamp, 93. Spirit level, its use, 84. Spoons, glass, 88. Spots, of transparency, 126 ; of opacity, 127. Stains, serrated, 125, 129; of development, 133. Statues, 185. Still-life, 187. Still, 92. Studio glass described, 57. Sun-printing, 218. Swing camera back, 74. Taste, cultivation of, 173. Temperature, modes of equalising, 62, 240; exciting, 102; effect of, on exposing, 105 ; developing, 107 ; albumenizing, 212; toning, 239. Test papers, 96. Thermometers, 89. Toning process, 222; bath, formula, 238. Under-exposure, 106, 109, 123. Yarnish, yellow, detrimental in copying, 189. Varnishing the picture, 116, 117. Ventilator, Arnott’s, 64. Vernis Soehnee, 118. Washing, glasses, 80 ; prints, 225. Wash-leathers, to prepare, 95. Waviiiess, 123. ^ 256 INDEX. Wedgewood trays, 87. Weights and Measures, English and Erench, 248, 249. White light, effects of, 66. AVhite rings, 125. THE END. PRINTED BY J. E. ADLARD, BARTHOLOMEW CLOSE. A LIST OF BOOKS PUBLISHED BY JOHN CHURCHILL. NEW BURLINGTON STREET. MR. 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