ilm (available
in 2-1/4" x 3-1/4" film packs) with battery-operated cameras having
lenses without diaphragms:

Black powder print on white or light background--snapshot
Gray or white powder print on black or dark background--1 second

These same exposure times can be used on some cameras having lenses
with diaphragms, provided the lens opening is set at f6.3.

The above exposure times are for cameras with batteries in average
condition. If batteries become weak the exposures may be increased
slightly.

In making snapshots the shutter mechanism should be manipulated as
rapidly as possible since slow motion will appreciably lengthen the
exposure. In making time exposures the camera shutter must be held
open for the desired time. Personnel with photographic experience may
desire to use cut film with the fingerprint camera. A few tests will
determine the optimum exposure times for any particular type of film.

Briefly, the procedure for taking photographs of latents is as
follows: The film pack is placed into the film pack adapter with the
safety paper side of the film pack to the slide side of the adapter,
care being taken to see that all of the paper tabs are outside of the
adapter. The adapter is placed on the camera in its proper position by
opening a slide clamp attached to the camera, fitting the side of the
adapter into the slot away from the clamp and pushing it down flat
into the opening. Don't try to slide the adapter into the opening from
the top. The adapter is locked in position by closing the clamp. Next
the slide is removed and the tab marked "Safety Cover" pulled out as
far as it will come and torn off. The camera is placed in position and
the first exposure made; then the tab marked "1" is pulled and the
next film is in position for exposure. This procedure is followed with
each succeeding film until all have been exposed.

When the last tab has been pulled out, the pack can be removed from
the adapter in daylight. If all of the films have not been exposed the
slide is replaced into the adapter and the film pack removed from it
in a darkroom, as previously stated.

As a matter of regular policy, it is recommended that more than one
exposure be made of each latent, varying the normal exposure time to
insure satisfactory results, especially when the contrast is not a
good black on white or gray on black.

Before starting to photograph, note the following:

- Check shutter action.