the actual frame position to help identity the cause, such
as improper handling, processing, or other lab or
maintenance procedures.
Image Analysis
Image analysis consists of density measurements
made with a densitometer. The properties to be
evaluated should include D-min, D-max, density range,
and gross fog.
Laboratory Evaluation
Whenever possible, you should use samples of
unexposed sensitized materials from the mission to
produce sensitometric measurements and standards.
This data should be used for comparison with the
mission film after processing.
POST-MISSION MAINTENANCE
EVALUATION
Photographer's Mates working in the Aerial
Processing section must be able to supply accurate
maintenance feedback information to the
reconnaissance system maintenance crews. Since the
end results are a true measure of system performance,
this feedback will do the following:
Ensure that maintenance personnel become
aware of possible system malfunctions.
Aid in evaluating overall system performance.
The process of evaluating a photographic negative
to determine system defects, as related to overall
performance, is one of the most complete measures of
system output. System defects noted during film
evaluation should be recorded on a film maintenance
feedback form and forwarded to maintenance personnel
for action.
Frame Spacing
On all serial-frame camera imagery and panoramic
camera imagery, you should include a space between
each exposed film frame. While the space may differ
in width requirements, it should be present. Frame
spacing defects generally indicate that a system defect
exists, such as a fault in the film-advance mechanism.
Image Overlap
Image overlap between successive frames provides
stereo viewing capability and distortion-free imagery
for a mosaic.
Instructions by the camera manufacturer contain
tables with overlap specifications for serial-frame
cameras and panoramic cameras. If the overlap is not
met, the camera may be receiving an improper V/A
(velocity/altitude aboveground level) signal from the
system. In addition to improper overlap, this problem
can cause blurred images.
Data Block
Each frame contains a data block and other
pertinent information about the mission, such as film
and flight direction, frame count, and so forth. In an
infrared reconnaissance set (IRRS), the data block is
usually recorded along the length of film periodically.
Discrepancies in the image of the data block are usually
caused by a malfunction within the sensor (camera or
IRRS).
Static
When film loses or gains electrons (negatively
charged particles), the film becomes either positively or
negatively charged. This charged material seeks to
return to a neutral state by transferring electrons from
or to other objects. This transference can sometimes
cause heat and light.
When light occurs, it fogs
unprocessed film emulsions and causes markings on the
processed film. These markings may have a spider web
or lightninglike appearance.
Shutter Banding
Banding is associated with focal-plane shutters. It
is caused by defective shutter operation. Banding can
be identified by the presence of uneven illumination
streaks across the line of flight. This defect is caused
by the focal-plane shutter slit, varying in size, and an
erratic shutter curtain or erratic film transport through
the focal plane during the exposure cycle.
Camera Light Leak
A camera light leak is often difficult to recognize.
It can cause various nonimage-forming shapes and
appear and disappear as the angle of light to the leak
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