Further comparisons of the KC-1 camera lens results, obtained on 
the T-4 Goniometer by each operator, and the calibration certificate 
published by Fairchild Camera & Instrument Corporation, show the 
largest deviation from the photographic method is 7 microns, with 86 
percent of the readings within +5 microns and 61 percent of the read 
ings within +3 microns. The calibrated focal length has better cor 
relation, with three operators within 1 micron of the photographic 
method and one operator each at 2, 3, 4 and 7 microns deviation. 
CONCLUSIONS 
Calibrations made with the Wild T-4 goniometer equipped with a 
No. 73 Wratten filter on the eyepiece and a fluorescent light source 
to illuminate the targets are sufficiently accurate for aerial mapping 
cameras. Results of calibrations made with the goniometer closely 
correlate those made with the field calibration range and the multicol 
limator. Readings made by four individuals in several observations 
agreed closely, indicating that a high degree of precision can be 
attained with this device. 
Only radial distortions could be measured with the goniometer 
tested. A new graduated plate having plus-type (+) targets and a 
filar-type eyepiece, however,would permit calibrating tangential 
distortions as well. A new model of the goniometer has such improve 
ments . 
ACKNOWLEDGMENTS 
The author wishes to acknowledge the assistance provided by the 
following in conducting this investigation: Mrs. Clarice Norton, 
Fairchild Camera & Instrument Corporation; Dr. Francis Washer, National 
Bureau of Standards; Messrs. Eldon Sewell, Robert Livingston, and 
Clyde Berndsen, U. S. Army Engineer Research and Development Labora 
tories; and Mr. Leon Kosofsky and Lt. Thomas Warnock, Aerial Recon 
naissance Laboratory. 
4