mechanics and other fields of engineering. 
4, RECOMMENDATIONS 
Based on the indications of the theoretical and experi- 
mental studies outline briefly in the preceeding section, it 
would seem that the following characteristics and capabilities 
are very desirable in an ideal universal stereometric camera: 
a. Base length changeable at will. 
b. Convergence between the chamber optical axes to be 
introduced and changed at will. 
General and differential tilt of the chambers 
optical axes to be introduced and changed at will. 
Possibility of rotation of the stereometric camera 
around its vertical axis. Also important is a possi- 
bility of locking and retaining the base at any 
desired orientation. 
Range of focussing should adequately cover distances 
from 0.5 meter to 100 meters or so. This range of 
distances is often encountered in engineering close- 
range work. It would be preferrable to have the camera 
with fixed focus at discrete stops. Calibrated spacers 
might be a reasonable solution in this regard. 
The individual chambers and lenses should be of very 
high quality. The characteristics and geometrical 
qualities of such items should be made known to the 
user of the camera. (This is usally not the case 
with the currently available stereometric cameras). 
Obviously, if the principal distance of the camera 
is changeable, the calibration parameters should 
be determined at each of the discrete stops of focus. 
Provisions for a viewfinder in each of the two 
metrical chambers, and the incorporation of both