GB707459A - Autograph stereophotogrammetric plotting apparatus with binocular stereoscopic vision - Google Patents

Abstract

707,459. Stereogrammetric apparatus. NISTRI, U. March 27, 1951 [March 28, 1950], No. 7031/51 Class 97(1) In a stereophotogrammetric plotting apparatus of the type described in Specification 463,879 in which two projectors project the stereoscopic images for viewing in two semi-transparent mirrors fixed in relation thereto through which plotting marks are also viewed by collimated light, each translucent mirror is fixed to its associated collimator, which may be of fixed or variable focal length, mirror and collimator being mounted in a cardan joint for universal rotation about the centre of the projecting objective to permit the use of wide angle objectives both in taking and projecting. Fig. 1 shows one of the projectors 1 light from which is reflected by the interface between prisms 11 and 12 fixed to a casing 5 mounted in a cardan joint 2 about the nodal point of the projecting lens. Within the casing 5 is a telescopic system 10 variable focal length collimating light from a plotting mark 8 moved according to the contour being plotted. The collimated light from the system 10 is reflected by the said interface and by the two outer surfaces of the prism 12 to pass through the interface in coincidence with the reflected beam from the projector. By movement of the casing 5 about the cardan joint a wide angle of plotting may be obtained. Alternatively the mark 8 may be fixed in the casing 5, the system 10 then being of fixed focal length, or the axis of the telescope may coincide with that of the projected beam reflected by the prism interface.