Canon Mirror Lens 3.8/800mm

extremely rare and impressive ultra-telephoto mirror lens, very bright maximal aperture F:3.8, made by Canon to order only in the 1960s, here in FL mount, it was also available in mounts for motion picture cameras, Canon advertised this lens as a 'World Brightest Lens' and it was pictured in very few brochures along with the infamous 11/2000 and 14/5200mm mirror lenses, length 58cm incl. camera mount, weight 15kg, the lens is in beautiful, probably unused condition, perfect optics, incl. large metal front cap, in the original aluminium carrying case, only a few of these lenses are known to exist and no recent sales have been recorded.