ee mm 
13 
In comparison to the hitherto usual wide-angle lenses with f = 15 em (6") such super 
wide-angle lenses cover nearly the threefold area and this with all the advantages of 
vertical photographs (fig. 1, tab. 1). 
Arrangement of the Overlap. 
1. For flat terrain in which the height differences À in comparison to the average flight 
altitude shows a maximum of about 1/10 H it suffices to take the photographs of a 
strip with a longitudinal overlap of 60% and a side overlap between 15 and 30%. 
2. For carrying out a well tied block triangulation the longitudinal overlap should be 
preferably 80% and the side overlap 60%. This is recommended also for larger dif- 
ferences in the terrain elevations up to 4/10 H. 
Utilization of the Photographs. 
The photogrammetric records can be utilized as follows: 
1. Stereoscopic observation and direct interpretation of the original pictures with a 
Mirror Stereoscope and Stereomicrometer. 
2. Production of enlargements in an Enlarging Printer for negatives up to a size of 
23 X 23 em (9 X 9”), for interpretation, identification, selection of ground control 
points for the aerotriangulation, entering of project sketches and interpretation results. 
3. Utilization of the photographs for the amplification of the number of fixed points by 
aerotriangulations. For this task the following instruments are suitable: 
a) Special Autograph for super-wide-angle photographs for aerotriangulation by 
spatial connection of successive photographs. 
b) Stereocomparator with electric registration of the picture coordinates and paral- 
laxes, and employment of programme controlled automatic computing machines for 
analytical aerotriangulations. 
c) Radial Triangulator for measuring angles and the separate determination of 
position and height of the auxiliary control points. 
d) Radial Punch for the slotted template method for the determination of planimetric 
control points. 
4. Production of controlled mosaics with the Rectifier. 
5. Production of stereoscopic prints according to the anaglyph process with the aid of 
the Rectifier. 
6. Plotting the planimetry and altimetry of the individual picture pairs: 
a) with the Special Autograph for super-wide-angle photographs (3a); 
b) with simpler ploting apparatus. 
The development of the photogrammetric equipment presented some particular pro- 
blems for the super-wide-angle lens, the special Autograph for aerotriangulation and 
plotting of super-wide-angle photograps and the simpler equipment for small-scale 
plotting. On the other hand such equipment as the stereocomparator, radial triangulator, 
radial punch, enlarging printers and rectifiers of standard construction are also suitable 
for the utilization of super-wide-angle photographs. 
In the following the construction principles for the development of the super-wide- 
angle lens, the new camera and the special autograph are to be described. 
The new Camera Lens. 
The experiences made with the 90° Aviogon lens showed that the super-wide-angle 
lens should meet the following requirements, listed in the order of their importance: 
1. Angular field of 120°. 
2. Relative aperture f : 5.6. 
3. Corner brightness of at least 15% of the brightness in the middle of the picture, and 
this also for the fully opened diaphragm. 
4. Maximum distortion = 0.01 mm.