F-71 Mirror Stereoscope

The standard for foresters, geologists, geographers, city planners, engineers, and military photo interpreters! One-piece cast aluminum body holds the precision mirrors at a stereo base approximately 11 " , permitting the operator to have complete separation of 9-1/ 2 " x 9-1/ 2 " aerial photographs containing a normal amount of overlap. Four legs fold for easy storage. Viewing lenses are set at a universally comfortable interpupillary distance. Optical system consists of two high-grade first surface vapor coated mirrors, two 45° prisms free of color fringe, and two precision-ground diopter lenses of approximately 11-1/ 2 " focal length. Common field of view is 5 " . Prism and lens are sealed to keep out dirt. Dimensions: 6 " x 7 " x 19 " . Magnification: 1x, 1: 1 ratio.