Precision camera for testing lenses

Abstract

Apparatus particularly adapted t o the testing of airplane camera lenses and complete airplane cameras is described. Seven collimators provide optically distant targets spaced five degrees. These targets are photographed by means of the lens or camera to be tested. An examination and measurement of the resulting negative gives the back focal length, equivalent focal length, and both distortion and quality of definition over the entire field of the lens. This instrument was designed and built for making the tests that are required by all contracts for Government mapping projects.