138 
device to 
CA—M camera also has a printing 
imprint into the frame intervals the photometric wedge 
illuminated by reference light source. This device 
guarantees the accuracy of photometric measurement on 
multispectrai images. 
The device design provides for photometric wedge 
and surveyed area exposure by the same time of 
exposure and this excludes the influence of 
non-interchangebi1ity effect (SchwarzschieId Law), 
which is of great importance for guaranting the 
required accuracy of photometrical measurements. 
Technical specifications of the photometrical 
wedge imprinting device 
Wedge wid t h — 
Wedge constant — 
Minimum optical density- 
Wedge image densities 
deviation of standartized 
values — 
Difference of inter—zones 
wedge image density values - 
Stability of shutter operation 
Deviation of light intensity 
of the rerference light source 
6 mm 
0.01mm 
0.1 D un- 
less than 15 % 
less than 5 % 
- 0.5% 
—less than 1 % 
The compensation of the image shift is made by 
linear method, i.e. a displacement of photofilm at 
the accuracy of 3%. 
The aperture interlense CA—M camera shutter 
provide for film sensitivity layer exposure in the 
frame field and exposure of the image of photometric 
wedge in the interframe interval for all 4 channels.