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