DEVELOPMENT OF A NEW WIDE ANGLE AMERICAN LENS 
The 6-inch f/5.6 Geocon I, designed by Dr. James G. Baker, represents 
the first American attempt to meet the lens requirements. Laboratory 
tdsts showed significant gains in resolution and image quality. Only a 
slight vignetting coat in the filter was required to correct the field illumi 
nation. Distortion was 8 microns. The prototype, fabricated six years ago, 
was installed in a KC-1 camera in which the shutter, designed for the 
Planigon lens, limited the effective aperture to an effective f/8. Aerial 
tests verified the gains in image quality over the Planigon, which were 
observed in laboratory tests. Models were flat, and a definite increase 
in efficiency of plotting operators was noted. 
Two years ago, the second Geocon I was installed in a KC-4 camera. The 
Rapidyne shutter was redesigned to accommodate the f/5. 6 aperture, vh ile 
the platen, in accordance with modern requirements, was made plane within 
0. 00020 u . Distortion again was less than 10 microns. 
Again, aerial tests verified the resolution and image quality gains, and again, 
models were flat. Color film exposed in this camera was good. Some photos 
were unusual. The success of the Geocon I led to further design by Baker, 
which resulted in the formula for the Geocon IV. 
This formula predicts an AWAR of over 45 lines/mm on Plus X film, 
distortion that is substantially zero, and illumination characteristics which 
require only cos^ correction to produce an even distribution of light at the 
focal plane. The first two prototypes are now being manufactured by Kollsman 
Instrument Corp. for installation in the Fairchild KC-6A cameras, and initial 
testing at Fairchild indicates the predictions will be met. 
KC-6A CAMERA MAPPING SYSTEM 
The KC-6A camera (see Figure 1) was conceived by Fairchild engineers during 
the last half decade, specifically to meet the demands of modern, high speed 
vehicles. These demands include a fast lens, a fast shutter, image motion 
compensation of high accuracy, automatic exposure control, and synchronous 
exposure of two or more cameras. All of these features, including the new 
Geocon IV lens, and a device for recording verticality, are integrated into 
the KC-6A. As noted by Di Carlo and Eakin, the KC-6A is one of the com 
ponents of the Mapping and Survey Subsystem Geodetic AN/USQ-28. 
KC-6A Camera Characteristics 
Lens 
6" f/5. 0 Geocon IV, radial distortion 
less than 8 microns; tangential distortion 
less than 8 microns