(27) 
ECTIVES 
RADIUS 
J 
mm. 
Fig. 8 Distortion of Wild Aviotar lens, 210 mm, f:4-2 
United States of America 
All single lens cameras for civil use are calibrated at the United States 
National Bureau of Standards. Their calibration procedures were described in 
the Archives of the Sixth International Congress of Photogrammetry. A new 
multiple collimator calibrator in which the camera is mounted pointing vertically 
downward has been introduced since then and was described by Washer 17 . A 
calibrator of the same general design is being put into use at Fairchild 18 . 
One specification for 6" lenses requires the following distortion. 
Field angle (°). . . .0 5 10 15 20 25 30 35 40 45 
Distortion (mm)..0 0 +0-01 +0-02 +0-04 +0-06 +0-10 +0-11 +0-06 -0-11 
Tolerances are +0-05 mm from 0° to 35°, +0-07 mm at 40°, and +0-20 mm 
at 45°. 
The lenses for the 9 lens camera are calibrated by the National Bureau of 
Standards. The assembled camera is adjusted and calibrated by the Coast and 
Geodetic Survey, calibration being by photography of a test area containing 
100 targets. 
Cameras used by the United States Air Force are calibrated by them using 
either a multiple collimator method or a field calibration procedure. I he 
tolerances which they apply to the three cameras used are given in the following 
table. 
U.S.A.F. Calibration Tolerances 
K17 T5 Til 
Maximum distortion 0-18 mm 0-12 _ 0-12 _ 
Prism single 1 *5 nun. 1 *5 min. 
Tangential distortion 0-03 mm 0-02 mm 0-002 mm (?) 
Flatness of focal plane _ +0-0005 in. 
Filter wedge angle 3 min. 10 sec.