Kaleinar's 5N 100mm f/2.8 — a Soviet short-telephoto portrait prime with smooth rendering.
The Kaleinar-5N 100mm f/2.8 is a Soviet short-telephoto portrait prime. The N version was made for the Nikon mount and other variants exist; it is part of the Kaleinar telephoto line and is drafted here for M42 use. It served as a fast portrait-length lens in the Soviet range.
This is a manual-focus lens with a 100mm focal length and a maximum aperture of f/2.8, drafted for M42 use though the 5N designation denotes a Nikon-mount version. Focus and aperture are set by hand on the barrel and it is an all-metal short telephoto. Exact element figures and native mount details are not asserted here beyond the verified focal length and aperture.
At 100mm f/2.8 the lens is a portrait and short-telephoto tool, giving flattering compressed perspective and good subject isolation. Soviet telephotos of this type render smoothly with pleasant out-of-focus areas, suiting portraits and distant detail. It is chosen for its characterful rendering at a modest cost.
Used copies are affordable, but buyers must confirm the mount, as the 5N variant is Nikon-mount rather than natively M42. Inspect for haze, fungus and cleaning marks, confirm the aperture is clean and the ring works, and check focus feel. Verify the mount matches your camera or adapter before purchase, then adapt as appropriate to mirrorless.