MAKE A PINHOLE CAMERA

from about f/192 to f/384, you should
use a fast panchromatic film in order to
be able to give shorter exposures. Color
pictures can be made also with pinhole
cameras. In color work, only tests will
give you an idea of how to expose properly,
and what filters to use.
EXPOSURE: For a pinhole camera
which has a "lens" made with a #10
needle, and placed 5 inches from a fast
panchromatic film, the following exposures
might serve as a guide: (For best
results run exposure tests. Shoot several
shots, varying the time on each.
Develop normally and choose the best
negative for a standard of exposure.)
Bright subject in full sunlight, 8 seconds,
under thin clouds, 20 seconds: Average
subjects, in full sunlight 16 seconds,
under thin clouds, 40 seconds. Dark
subjects, under full sunlight, 40 seconds,
under thin clouds, 100 seconds. Indoors
use two #2 photo-flood lamps, one on
each side of the subject, pointed at it
from 3 feet away. Expose 1 minute.
PROCESSING: It is best to develop
film by inspection. However, the above
exposure guides are based on development
in Kodak Dektol, diluted one part
stock solution to three parts water, for
4 min at 68-degrees F with agitation.
VIEWFINDER: The most common way
of judging what areas will be included
in a picture made by a pinhole camera
is to sight from the center, back part of
the camera, at eye level, using the front
corners of the camera to designate the
right and left hand limits of the picture.
By holding your hand about 4 or 5
inches above the front section (this depends
on whether you're taking a
vertical or horizontal picture with your
4x5 camera), you can get an approximate
idea of your coverage.
FOCUSING: Since the "lens" opening
is somewhere within a few points on
either side of f/200, you need not worry
about focusing. Your picture will be as
sharp in foreground as background.
IMAGE SIZE: This depends primarily
on the distance of the film from the pinhole.
If the pinhole is 3 inches from a
4x5 piece of film it will produce a wideangle
effect. Using the sam~ film, but
moving the .pinhole 5 inches away, you
will get a view that could be classified
as "normal." Using the pinhole beyond
the normal focal length for 4x5 film will
start producing a telephoto effect. You
must remember that as you increase the
focal length of your pinhole camera, that
you are increasing the time of exposure
also. If on a pinhole camera with a
5-inch focal length the exposure in
bright sunlight is 16 seconds, the exposure
for a pinhole camera 10 inches
long will be slightly more than 4 times,
or about 70 seconds. For extra long pinhole
cameras it is best to run exposure
tests.
SHUTTER: Since most pinhole exposures
are long, a cardboard piece
hinged over the front of the pinhole
camera can act as a shutter. It is operated
manually. With flash, electronic or
flash bulbs, the duration of the light acts
as the shutter. The open-flash system is
used when working with flash. Open the
shutter, fire, and then close it.-I!!!
August. 1954