PROTOTYPE SLR camera Stereoscopic. German construction around 1910-1920. Manufactured by"" Peter Dietz"" in Copitz, East Germany. Format plates 6 x 13 cm. Lenses Hugo Meyer & Co. Goerlitz 6.8 / 90 mm. Marked on the front of the camera"" TETRANARE 1: 5.4 F: 90 mm O. SIMON DRESDE No. 11172- No. 11173"" . The only copy known worldwide. Not indexed, A discovery! A magnificent device. Original instructions with the name of the inventor, with an engraving the device.