16
As aero triangulations can be carried out by graphic determination of positions on
the drawing table as well as by reading of the coordinates, either with a constant base
length or by the method of consecutive pictures, and as the direct compilation of maps
on scales from about 1 : 20.000 to 1 :200.000 is possible for photographs taken with
wide-angle or super-wide-angle lenses after their format reduction, it is apparent that
the WILD A9 Autograph is a new universal instrument for small-scale cartography.
The Diapositive Printer.
For reducing the size of the photographs the new WILD U3 Universal Diapositive
Printer type À or B can be employed.
The optical data of this apparatus are as follows:
TABLE 2
U3 Universal Diapositive Printer: | A B
Focal length of the lens = | | 200 mm ry E . 100 em US
Transformation range | 1:16102:1 | 18:1t032:1
Largest negative size E 23 X 23 em | 23 X 23 cm
Largest diapositite size 0500 : EIN 23 X 28 em eer: 15 X 15 em
In addition to the residual lens distortion and the curvature of earth and refraction,
it is also possible to rectify the systematic film shrinkage during the copying process.
For example, the adjustment of the focal length allows the transformation of all photo-
graphs to accurately f = 44.00 mm, so that plotting can be effected without delay.
The negative is illuminated in the Diapositive Printer by a mercury vapor lamp
through an opal glass plate. A focussing screen is provided for observation of the picture
with magnifying glasses by means of a folding mirror. No details of the original photo-
graph are lost during its reduction to half size, on condition that diapositive plates of
fine grain are used. The obtained diminuated diapositive is fully equal to the original
photograph.
Summary.
The super-wide-angle camera lens ''Super-Aviogon" f:5.6 with the focal length
f — 9 em (31/,”) for the picture size 23 X 23 em (9 X 9”) and the WILD A9 Auto-
graph are important advances of great value for the economic compilation of small-scale
maps and particularly useful for the opening out of large territories.
