LIBRARY 
 FATE i-LANT BOARD 
 
 ET-143 April 1939 
 
 United States Department of Agriculture 
 Bureau of Entomology and Plant Quarantine 
 
 A LIGHT AND CAMERA STAND FOR PHOTOGRAPHIC COPY WORK 
 
 By Orin A. Hills and R. L. Wallis, Division of Truck Crop 
 and Garden Insect Investigations 
 
 A combined light and camera stand for use in copying line 
 drawings was constructed at the Grand Junction, Colo., field labora- 
 tory and has been found to be very convenient and time saving. The 
 stand with its lights as described gives an even distribution of 
 light over drawings up to 26 by 33 inches and is inexpensive to 
 construct. 
 
 Construction 
 
 The frame v/hich holds the reflector (fig. 1, a) and lights 
 (fig. 2, c) is constructed of 2- by 4-inch lumber and is fastened 
 together on the inside of the frame with shelf braces (fig. 3, h) . 
 The sides of the frame are extended downward to form the front legs 
 of the stand. The back legs are made of 2- by 2-inch pieces and 
 support the side arms (fig. 2, j). The legs are fastened by shelf 
 braces (fig. 1, h) to a base of 2- by 4-inch material, under which 
 are gliding casters (fig. 1, i) to facilitate moving the stand. 
 A 1- by 4-inch piece between these bases helps to stiffen the legs. 
 The ends of the board supporting the camera (fig. 2, b) are fastened 
 to each side arm (fig. 2, j) by a bolt with a wing nut (fig. 1, g) , 
 which passes through a slot running the length of the arm and per- 
 mits the camera to be clamped at any distance along the depth of the 
 stand. A graduated stick (cut from an ordinary yard stick) is 
 fastened to the inner edge of each arm to assist in clamping the 
 camera support (fig. 2, b) parallel with the front of the stand. 
 The camera is fastened to the camera support by a thumb screw in 
 the same manner as it would be fastened to a tripod. 
 
 The reflector (fig. 1, a) consists of two pieces (fig. 2, 
 ai and a 2) of 22-gauge galvanized sheet iron. The inner and outer 
 sides are flared 1 inch from the edges of the frame and are fastened 
 to the frame with small nails. The inside of the reflector is 
 painted .with white gloss paint to better reflect the light. 
 
 The light, sockets (fig. 3, d) are mounted in the frame in 
 holes which are just the size to hold them snugly. The sockets are 
 connected in parallel to a cord (fig. 3, k) which is plugged into an 
 electric outlet. Outside frosted, round, 25-watt globes are used. 
 
- 2 - 
 
 To facilitate centering the drawing on the wall in front of 
 the reflector a piece of fibre wall-board material was fastened to 
 the wall and ruled off in 1-inch squares, the lines running parallel 
 and perpendicular to the floor. Two lines were marked on the floor 
 to indicate the proper alignment of the stand. It was found that 
 three positions of the stand (15, 30, and 45 inches away from the 
 drawing) v/ould give opportunity for focusing on all sizes of draw- 
 ings which the apparatus would accomodate. These positions were 
 also indicated by marks on the floor. The position used will depend 
 upon the size of the drawing to be photographed. The time of ex- 
 posure given in table 1 was determined for each size of drawing. A 
 photograph of the complete set-up is shown in figure 4. 
 
 Table 1. — Exposure time for process films on f. 16 stop 
 (Time based on reduction or enlargement of 
 all drawings to full size of camera plate) 
 
 Distance of 
 light stand 
 from object 
 (Inches) 
 
 Longest diameter 
 or size of 
 drawing 
 (Inches) 
 
 Exposure 
 (Seconds) 
 
 15 
 
 30 
 45 
 
 10 by 14 
 20 by 28 
 
 to 
 to 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9 
 
 10 
 
 11 
 
 12 
 
 13 
 
 14 
 
 20 by 28 
 
 31 by 44 
 
 60 
 56 
 52 
 48 
 44 
 40 
 36 
 32 
 28 
 24 
 20 
 40 
 75 
 
 Operation 
 
 The stand is used in a room with the shades drawn to exclude 
 other light. A 5-by-7 camera with a stop opening of f. 16 and pro- 
 cess film are used. Any size and type of camera can be used pro- 
 vided it has a ground glass back for focusing and provided the lens 
 comes in the center of the reflector. The position of the stand 
 and the exposure time can be read from the table, and it remains 
 only to place the camera in such a position that the drawing will 
 occupy the full size of the camera plate when in focus. This is 
 done by the adjustment of the movable camera support. 
 
 On drawings larger than 26 by 33 inches the light becomes 
 less intense around the outer edges and the lighting is not entirely 
 satisfactory. 
 
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 Figure 1. — Side view of stand, a, reflector; b, camera support; 
 d, brass electric light sockets; g, ?ring nut and bolt for 
 holding camera support in position; h, shelf brackets used 
 for strengthening and bracing stand; i, gliding casters. 
 
Digitized by the Internet Archive 
 in 2013 
 
 http://archive.org/details/lightcamerastandOOunit 
 
28- 
 
 Figure 2. — ^Front view of stand, a, and b.^^ sides of reflec- 
 tor; b, camera support; c, light brilbs; e, slots to allow 
 for movement of camera support; f , cajnera; h, shelf brackets; 
 j, side arm on which camera si:5)port rests. 
 
21" 
 
 Figure 3« — ^Rear view of frame, d, bra-ss electric light 
 sockets J h, shelf "brackets for strengthening frame; 
 k, electric cord. 
 
Figure 4.. — Camera stand in position for operation. 
 
UNIVERSITY OF FLORIDA 
 
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 3 1262 09239 5192 
 
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