Keystone Stereoscopic Tester M1A1
718
Hammerpreis
360 €
inkl. Käuferpremium
Schätzpreis 500 € – 600
Zustand : B
solid American stereoscopic testing device for tele-binocular vision, constructed by Keystone View Co., all parts made of metal and with black crackle finish, heavy cast iron stand, precision adjustment for the sliding card holder engraved with rulers in millimetres and inches, the card holder is equipped with a micrometer adjustment gear shifting an airplane-shaped target from left to right. The device was very likely built for the Air force to test a pilots capacity of depth of field vision.