Effective focal length adjusting additional lens system for multispectral camera-projector

摘要

An aerial camera for the simultaneous photography of ground features taken on a plurality of pictures on a single monochromic film uses a plurality of lenses and a filter for each lens, so that each photograph is in a different spectral band. A plurality of additional lens systems are provided to optically adjust each camera lens as to its effective focal length, enabling the use of a uniform film platen in the camera. Additional lens systems of the same design may be used to adjust the focal length of each of the lenses of a multispectral projector and viewer to provide clear and sharp images.