● Remove slide and pull safety tab of film pack before making exposure.
● Hold camera still while making exposure.
● Pull correct number tab after each exposure (be careful not to pull more than one).
● Do not use grained or uneven material as a backing when photographing latents on transparent glass.
● Mirrors, polished chrome, and nickel plate will photograph black in the fingerprint camera.
The foregoing has dealt with the standard use of the fingerprint camera when the direct light afforded by the camera gives suitable results. There will be cases, however, where the results from the use of the direct light may not be adequate. Such cases may involve molded or embedded prints, such as prints in putty, wax, soap, etc. Should direct light give poor results, side lighting may prove effective. This can be done by loosening two of the bulbs on one side so that they will not light. The light given by the other two bulbs is directed so as to pass at right angles, as much as possible, across the ridges of the embedded latent print. Adjustment of the exposure time must be made when this is done.