nt 
‚05 
The effect of the aging of the photographs upon the systematic disturbances 
is investigated in one organization. 
The systematic disturbances of the photographs (primarily the radial 
distortion) is reduced in connection with the diapositive printing (6 organ- 
izations) or in the plotting instrument (8 organizations). In 3 organizations 
numerical corrections are applied. 
Compensating plates are especially tested in 8 organizations. The toler- 
ances of the radial distortion compensation vary between 0.002 and 0.02 mm. 
In most organizations the geometric qualities of the photographs are tested 
through ordinary plotting methods after photography of test fields. In one 
organization no effect of compensating plates has been found. 
3.2 How is the photographic image quality judged and tested? 
Do you think it is possible and suitable to measure and define image 
quality numerically and to construct numerical tolerances? 
22 answers, 
Visual examination and subjective judgement is used in 15 organizations. 
In some cases (5) also objective methods are used (densitometers). Eight 
organizations do not think it is possible to measure and define image 
quality numerically and to construct numerical tolerances. Nine organiza- 
tions point out the desirability of numerical definitions of image quality and 
numerical tolerances and think that such can be established in the future, 
after necessary research, 
3.3 How are the geometric qualities of reducing printers and similar 
instruments tested? 
Is the possible influence upon the geometric image quality of additional 
devices for improving the photographic quality particularly tested? 
22 answers. 
Nine organizations use grid tests for the check of reducing printers including 
devices for improving the photographic quality, and 6 use tests of stereo- 
scopic models over terrain test fields. 
3.4 How is the flatness of glass negatives, glass diapositives and similar 
material tested ? 
Which tolerances are accepted and how are the tolerances constructed ? 
20 answers. 
Four organizations test the flatness with interference methods and 4 organi- 
zations use pneumatic gauges. Tolerances are very different. In some