- Exposure 
The exposure meter regulates exposure time and aperture to provide the best possible exposure for 
the aerial photograph. In doing so, it takes into account the best possible aperture and the 
limits for the length of exposure, and displays any deviation from these. ; 
The functions that have been described are carried out about one hundred times a second while the 
equipment is in operation and the display is continuously updated. During exposure and film transport, 
the number of functions that are controlled is increased by the following: 
- Vacuum 
To avoid geometrical deformation, the film must be lying perfectly flat at the moment of exposure. 
For this reason, the actual vacuum is measured during exposure and compared with the required value. 
- Shutter-Blade Operation 
Exposure begins as the shutter blade opens and ends when it closes. This blade movement is 
detected by sensors and a check for correct functioning is made. 
- Projection of Fiducial Marks 
The lighting up of the fiducial marks is checked separately for each for function and duration. 
- Single/Serial Exposure 
With a long cycle time, it is possible without difficulty to release single exposures between two 
serial exposures. The later identification of such an exposure is made possible by the projection 
onto the film of a single/serial code. 
After exposure has been completed, quantitative data from the camera control and the operating aids 
are recorded on the film by means of a digital code. In addition, during film transport, the actual 
cycle time and the end of the film are also registered. Apart from a continual and updated display 
of all functions tested, their qualitative values are also recorded digitally on the edge of the 
film during film transport. 
Service Functions of the RC 10A 
The service functions of the RC 10A are accessible both to the operator and to the service mechanic. 
As a result, it is possible even in flight and with the camera kept closed to call up a meaningful 
self-check and diagnostic programs. By this means, functional defects or faulty modules can be 
immediately recognized. 
The service mechanic is enabled to identify defects down to individual-component level, by the correct i 
use of appropriate diagnostic programs and simple measuring instruments. Figure 6 shows the various Mi 
steps in the identification of defects by the customer and the service mechanic, with the camera kept B uo 
closed and opened respectively. 
FAULT FINDING II 
CAMERA OPEN (DISMANTLE | 
  
  
  
  
  
SERVICE MECHANIK 
CAMERA CLOSED [] 
OPERATOR 
COMPONENTS e 
CIRCUITS [- | SIGNATURE ANALYSIS] 
MODULE m | TEST-POINT MEASUREMENT | 
FUNCTION | VISUAL CAMERA CONTROL ] 
[ SELF-TEST /DIAGNOSTIC PROGRAM 1 
  
Fig ©: Methods and Steps of Fault Finding 
112