In order to exploit the quality of the lens better than film would permit, Wild 
developed the RC7 fully automatic plate camera, which was on display in Holland as 
early as 1948. This camera uses 15 X 15 cm (5-91") plates, and its Aviotar lens has a 
focal length of 17 cm (6-69"). 
However, the expectations of practical photogrammetrists were only partly filled by 
the Aviotar, on account of its being a normal angle lens. This type of lens is unsuited for 
adaptation to wide angle photography. Thus, the quality gap between normal angle and 
wide angle lenses was only further widened by the Aviotar. The next step consisted in 
the development of an entirely new type of lens, which had to fill far more extensive 
and stricter requirements than the Aviotar. In addition to an excellent definition for 
low contrasts, a markedly improved brightness had to be obtained than was afforded 
by the former wide angle models. In such lenses, when they are used wide open (at 
f/5-6), brightness at the edges of the picture does not exceed 10 to 12 °/ 0 of what it is 
in the center. This brightness had to be multiplied by a substantial factor, three at the 
very least. Furthermore, the lens also was to be free from diaphragm irregularities, and 
present as small a distortion as the Aviotar, namely less than -01 mm. 
Whatever existing physical laws on light distribution in photographs there might be, 
L. Bertele, who developed the Aviotar, succeeded in creating a wide angle lens, with 
an f/5-6 opening, which was named Aviogon. This lens is so excellent that it is used 
not only in the RC5 film camera, but also lends itself to adaptation to the RC7 plate 
camera, particularly for strip radial triangulation and large scale surveying of open 
terrain. 
WILD PH 106 
Longitudinal section through «Aviogon» wide angle lens 
With the development of these two lenses, the camera problem enters its final phase, 
in-so-far as modern concentrated photogrammetry is concerned. 
The RC5 film camera, improved upon in the meanwhile, can now be used with three 
different cones. They are: