USAF TYPE T-ll MAPPING CAMERA* 
Leonard W. Crouch, Engineer, Photo Reconnaissance Laboratory, 
Wright-Patterson Air Force Base, Ohio 
HE Air Force Type T-ll Mapping Camera was designed to fulfill require- 
X ments within the military services for a mapping camera to supply pre 
cision photography for the photogrammetrist. Besides need to meet the pre 
cision requirements, this camera had to be rugged, simple, and easy to operate 
and maintain from the military standpoint. The general characteristics of the 
camera are as follows: It utilizes the 6"//6.3 metrogon lens; it has a shutter 
speed range from 1/10 to 1/500 of a second; it has data recordings; a shutter 
synchronizer pulse to actuate external recording devices; and a film capacity of 
390 feet of 9| inch wide film. 
Designing these characteristics into a mapping camera in such a way that 
the precision, ruggedness and simplicity requirements are met, presents a very 
formidable engineering problem. There are always very obvious and complicated 
paths to follow in order to have a given design meet a set of precision mapping 
requirements, and it is only through much thought and redesign that ruggedness 
and simplicity of equipment are finally forthcoming. To achieve this end in the 
Type T-ll Camera it was decided to adopt and blend together certain basic 
features. First of these was to have the precision relationship between the optical 
elements and focal plane contained in an inner cone and the magazine platen; 
this was to make possible a camera possessing utmost precision and yet being 
simple to manufacture, operate, and maintain. The second feature was to use the 
Rapidyne drawer type shutter; this would permit the utilization of a high speed, 
efficient intralens shutter that could be removed from the lens cone without 
disturbing the optical elements. The third and very important feature was to 
strive for use of readily removable compact sub-assemblies throughout the entire 
camera; this would greatly simplify the camera maintenance problems, thereby 
increasing the reliability of the camera. When the final camera design incorpo 
rating these features was completed, the result was a mapping camera having 
the precision required by the photogrammetrist, the simplicity desired by the 
photographer and camera maintenance man and, above all, the ruggedness de 
manded by its use in military operations. 
The camera magazine does not have forward motion compensation. This is 
made possible by the present day image velocities at mapping altitudes. Should 
these velocities become great enough to reduce appreciably the quality of the 
photography, the forward motion compensation feature will be designed into the 
camera system. The camera magazine as we know it today, contains a divided 
film compartment, a vacuum sensing and recording device, a removable case 
drive and the platen, or vacuum back. The divided film compartment was pro 
vided to facilitate loading of film into the magazine while in the dark room; this 
requires only the supply chamber to be loaded in the dark and the remainder of 
the loading procedure can be accomplished in the daylight. The magazine platen 
has been carefully designed to provide a film positioning surface that is flat to a 
tolerance of ±5/10,000 of an inch. Special reinforcing of this unit assures the 
photogrammetrist that the film positioning surface will retain its flatness 
throughout the life of the camera. Located at the vacuum input of the platen is 
the pressure sensing device which provides the signal for the vacuum recording. 
This feature in the camera is of considerable importance. It registers an image 
* Prepared for Seventh International Congress. Permission for publication granted by Inter 
national Society of Photogrammetry. 
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