component derived also from computation. For this purpose, it seems more con- 
venient to make use of the knowledge of the distance between two control points 
because, in this case, the instrument becomes extremely simple due to not needing 
any indication in the camera supports, the function of which would thus only be 
that of making the cameras take the desired position. 
For the adjustment and control condition of the instrument, it is necessary to 
ascertatin at the beginning with a level, the position of the intersection between 
the horizontal reference plane and the axis passing through the center of the camera 
optics and perpendicular to said plane. This is for the purpose of bringing the 
nadiral point of the photograph to coincide with this point of the plane. 
But a more suggestive possibility appears which would permit the decisive 
simplification of photogrammetrical plotters, returning them to their only and 
true function, which is plotting or autographic tracing of the topographic map. 
This possibility may be attained with the transformation of the original photograph 
into the corresponding vertical axis photograph with prefixed geometric charac 
teristics which can be common to all plotters, regardless of those of the aerial camera. 
For these plotters it will be sufficient that the camera support permits only 
rotation p, that is, around the axis perpendicular to the horizontal reference plane, 
and it will be necessary and sufficient, as adjustment and control condition, that 
the camera axis coincides with this axis perpendicular to said plane. These supports 
can maintain the movements necessary for the setting of the base components, 
but indeed it will be sufficient to maintain only the base component b,. 
[n order to attain this possibility, as already stated, an auxiliary instrument 
is necessary, which permits obtaining new photographs answering the indicated 
conditions. The instrument exists and it is the Telescopic Photoprinter, designed 
and produced by me. 
It is an instrument which must possess particular precision qualities because 
it must repeat the data of w and ¢ values derived from computation, and the interior 
orientation of the camera, which controls in its turn the new photograph. But be 
cause these very exact conditions are applied to only one camera, the function of 
which, besides, is much simpler than that of the plotter cameras, its cost will always 
be much less than that of a plotter of first order precision. 
Besides, it is a single instrument which can serve numerous plotters of greater 
performance and having characteristics much less stringent than the present ones. 
As I already indicated, photographs having unique and determined geometrical 
characteristics are obtained with the telescopic photoprinter, so that it will be possi 
ble to unite all the plotter cameras, thus attaining a further economy in their 
construction and their practical use, because all the Cevices in use today to adapt 
them to the photographs of the various exposure cameras can be abolished. 
I will not give a description here of the instrument, which I have called « Tele 
scopic Photoprinter », because this was already done, (2) but I will point out the way 
that this can become a part of the new technique for commercial use of photo 
grammetry. 
[ envisage, therefore, organizations specialized in the performing of only aerial 
(2) Gino Parenti - « The NISTRI-OMI Telerectoprinter » 26th Annual Meeting Ame 
rican Society of Photogrammetry - March 23-26, 1960.