Advanced Photography Course

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

4-38

contents

Advanced Photography Course

<- previous page

next page ->


DOFMaster for Windows On-line Depth of Field Calculator DOFMaster for Mobile Devices On-line Depth of Field Table Hyperfocal Distance Chart Articles FAQ Recommended Books Support Contact Links Home As an Amazon Associate I earn from qualifying purchases.	contents <- previous page next page -> 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 4-38 contents Advanced Photography Course <- previous page next page ->	As an Amazon Associate I earn from qualifying purchases.
	WWW.DOFMASTER.COM © 2006 Don Fleming. All rights reserved.