Rubinar's MC 1000mm f/10 — an extreme compact Soviet M42 catadioptric mirror telephoto.
The MC Rubinar 1000mm f/10 is a Soviet, later Russian, catadioptric mirror telephoto lens made in M42 and other mounts. Using a Maksutov-type mirror design, it delivered an extreme 1000mm focal length in a barrel far shorter than any refractive equivalent, for very distant subjects.
This is a manual-focus M42 screw-mount catadioptric lens with a 1000mm focal length and a fixed effective aperture of f/10. As a mirror lens it has no adjustable diaphragm, exposure being set by shutter and ISO or filters, and focus is by hand. It is a stout lens for such reach. Exact weight and element figures are not asserted here beyond the verified focal length and aperture.
At 1000mm the lens reaches extremely distant wildlife, the moon and far landscape detail in a compact form for its power. The central mirror obstruction gives the characteristic ring-shaped out-of-focus highlights of catadioptric lenses. The very long focal length and fixed aperture demand a sturdy tripod and careful technique for sharp results.
Used copies are affordable relative to refractive super-telephotos and valued for their portability at this reach. Inspect the mirror optics and front glass for haze, fungus and coating issues, confirm smooth focus, and check the mount and tripod fitting, which is essential at this focal length. There is no aperture to test. An M42 adapter allows use on mirrorless with a solid support.