substantially improved overlap control, Further, very useful 
improvements resulted from the data records that could be 
exposed on to the frame corners, comprising frame number, 
time of day, and a box level for tilt information. The deve- 
lopment of wide- and superwide-angle lens cones (f = 100 mm 
or 75 mm, respectively) complemented the existing range of 
focal lengths to great advantage, 
Let the great number of camera versions, which left the Jena 
works between 1930 and 1940 and which differed mainly by 
their frame sizes and focal lengths, be exemplified here by 
the RMK 20/3030 Wide-Angle Mapping Camera produced in 1936. 
It had a 200mm f/6.3 Topogon lens designed in 1933 by 
R.Richter, This first wide-angle aerial lens marked a new 
stage in the development of aerial photography, The angular 
coverage was 105 gon, corresponding to a frame size of 
300 mm x 300 mm, Compared to the normal-angle lenses which 
by that time had been the only available aerial photolenses, 
the Topogon brought a remarkable progress with regard to 
capturing a larger ground area from the same flying height, 
The RMK 20 had a between-the-lens leaf shutter, with selec- 
table speeds between 1/25 and 1/250 s, Selectable f-stops 
were 6,5, 9 and 12.5. : 
Convenient operation, by the standards of the time, of all 
aerial camera models was possible by means of the IRU Universal 
Control Unit (Fig.7), which provided stepless control of 
frame and, thus, of overlaps between 10% and 90%. The unit 
also contained a drift meter, ground-glass viewfinder, pulse 
transmitter, switches and pilot lamps. Connection between 
the IRU and the camera was by cable, which afforded a welcome 
freedom of arrangement within the aircraft. 
2, THE DEVELOPMENT OF AERIAL PHOTOGRAPHIC EQUIPMENT 
IN JENA AFTER 1960 
The first MRB 21/1818 Aerial Survey Camera (Fig.8) that left 
the Jena plant in 1961 marked the, beginning of a new epoch 
of aerial camera design in Jena. Its designers had, from 
the start of their post-war efforts, oriented themselves 
by international standards and requirements, The MRB 21/1818 
reflected both the requirements and possibilities of the time, 
It was a normal-angle camera with a frame size of 180 mm x 
180 mm and a 210mm f/4 Pinatar lens. The outfit comprised 
four units, viz, mount, camera proper, magazine and control 
unit, The control unit contained all control and monitoring 
elements of the system and enabled its remote operation. 
The rotary blade shutter had a high efficiency and steplessly 
controllable speeds between 1/100 and 1/1000 s, The optical 
specialists at Jena met the grown demands for high-performance 
lenses by designing in 1962 special lens testing devices such 
as a distortion tester, an image quality tester and a flatness 
tester, These new facilities had a favourable effect on the 
development of high-performance lenses such as the 115mm f/4 
Lamegon (1964), which formed part of the wide-angle 
MRB 11.,5/1818 camera, The Lamegon was the first wide-angle 
lens to have a relative aperture of 1:4, Yellow and orange 
63