o secure impressions by inking and rolling in the
regular way or, should this fail, ordinary photography will certainly
give satisfactory results. For economical and practical purposes the
use of the X-ray is not recommended.
_General photography_
In the foregoing instances in which it has been impossible to obtain
suitable inked impressions it will be noted that the last resort has
always been photography. In all probability in advanced cases of
decomposition, desiccation, and maceration it may not be possible to
secure inked impressions which can be properly classified. Hence, it
will be necessary to photograph the ridge detail. Accordingly, there
are outlined below several methods of photographing the ridges which
have been used with success.
In photographing the ridge detail on fingers it has been determined to
be most practicable to photograph the finger natural, or 1/1, size
inasmuch as comparisons will usually be made with inked impressions
which are natural size. Any camera built or adjusted to taking 1/1
size pictures, and with which the lighting may be arranged to best
advantage, may be used.
There is a wide choice of film which can be used for this purpose. The
so-called soft films are all good for photographing ridge detail on
fingers. Process film is not recommended inasmuch as the film presents
too much of a contrast. Consequently, if it is used, some of the ridge
detail will be lost, especially if wrinkles are present in the skin.
Lighting is accomplished by the use of gooseneck lamps, floodlights,
or a spotlight. If a fingerprint camera is used, its lights may be
sufficient.
The manner of lighting may be by direct light, side light, transmitted
light or reflected light, depending upon the prevailing condition of
the finger or skin.
Direct light is used in those cases in which the ridge detail is
fairly clear and there are no wrinkles present; or, if wrinkles are
present, they are not deep enough to interfere with photographing the
ridges.
Side lighting is used when there are no wrinkles of any consequence
and the ridge detail is clear but because of discoloration the ridges
are not readily seen in the ground glass as there is lack of contrast
between ridges and depressions. Accordingly, the lights, instead of
being focused directly on the skin or finger, are placed to the side
of the object so that the light is directed across the skin or finger,
thus highlighting the ridges and shad
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