FATE PLANT 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. W.'allis, 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 lime 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
The frame which holds the reflector (fig. 1, a) and lights
(fig. 2, c) is constructed of 2- by 4-inch. lur.,ber and is fastened
together on the inside of the frame with shelf braces (fig. 3, h).
The sides of the frame are extended dowvnard 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). Tne legs are fastened by shelf
braces (fig. I, 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,
a1 and a2) 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.
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) would give opportunity for focusing on all sizes of draw-
ings which the apparatus would accommodate. 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 Longest diameter
light stand or size of
from object drawing Exposure
(Inches) (Inches) (Seconds)
15 4 60
30 10 by 14 to 20 by 28 40
45 20 by 28 to 31 by 44 75
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 drawiiigs larger than 26 by 33 inches the light becomes
less intense around the outer edges and the lighting is not entirely
,I 1 !
Figure l.-Side view of stand. a, reflector; b, camera support;
d, brass electric light sockets; g, wing nut and bolt for
holding camera support in position; h, shelf brackets used
for strengthening and bracing stand; i, gliding casters.
i 6.- 33"
28" ^ "
N--N--N-_ | I-
Figure 2.-Front view of stand., a- and a2, sides of reflec-
tor; b, camera support; c, light bulbs; e, slots to allow
for movement of camera support; f, camera; h, shelf brackets;
j, side arm on which camera support rests.
Figure 3.--Rear view of frame, d, brass electric light
sockets; h, shelf brackets for strengthening frame;
k, electric cord.
Figure 4.-Camera stand in position for operation.
UNIVERSITY OF FLORIDA
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