TEENS TEST AT
HH EE E ERR
a
b) in view of the substantially improved efficiency of the new camera objectives,
films as picture carriers can no longer give maximum results because their
shrinkage is a multiple of the residual distortion of the new optics. For large
scale precision mapping, specially prepared glass plates are therefore now used
as picture carriers;
c) in order to profit fully by the improved angular precision of the new object-
ives of highest efficiency, it is necessary that stereoscopic plotters be further
developed, such as further improvement of the optical and mechanical adjust-
ment of the measuring system, an increase in the stability of the adjustment, the
use of optical correcting plates for the compensation of still existing residual
distortion errors.
I personally believe that the tendency to increase the sizes of the photographs
is a sign of insufficient optical and mechanical factory output. There are most
favourable picture sizes with which a maximum of angular precision of the ray’s
bundle can be obtained. Given highest optical manufacturing efficiency, it seems to
me that the most suitable sizes for plates should be 15X15 cm and for films
18X18 cm.
Regarding the photographing equipment it is to be pointed out that the auto-
matic serial cameras at present built in preference by the industry, do not always
attain the desired results. Especially for the large-scale precision photogrammetry
in the mountains it is necessary to give a wider scope to the choice of external orien-
tation. Besides vertical photographs, one must be able also to take convergent pairs
of photos with 100% overlap. The development of air cameras allowing a larger
choice in the selection of the external orientation is an important claim of large-
scale precision photogrammetry.
In stereoscopic plotters, the photogrammetric determination of boundary
points will play an increasingly important role. Here, as well as in air traversing,
equipments for the automatic registration of spacial coordinates of the reconstruct-
ed points and for the economic transformation of these coordinates into coordi-
nates of the geodetic system of the country, have become important.
