Tokina's constant-aperture manual tele-zoom — RMC 80-200mm f/4, one-touch design sold across major SLR mounts.
The RMC Tokina 80-200mm f/4 was a manual-focus telephoto zoom sold by Tokina from the late 1970s into the early 1980s under its RMC (Rainbow Multi Coating) branding. As a third-party alternative to the camera makers' own 80-200mm zooms, it was produced in fixed versions for most major SLR mounts of the period, including Pentax K, Canon FD, Nikon F, Minolta, Olympus OM and M42, and sat in Tokina's range as the mainstream constant-aperture tele-zoom.
It covers 80-200mm with a constant f/4 maximum aperture, stopping down to f/22, and takes 55mm filters. The lens is a manual-focus design built with the one-touch layout typical of the era, in which a single collar is pushed and pulled to zoom and turned to focus. Aperture operation is automatic via the camera linkage on the bayonet-mount versions, and the barrel is all-metal construction of the period.
Stopped down a stop or two the lens delivers respectable sharpness and contrast for a 1970s third-party zoom, while wide-open performance at the long end is softer, as was normal for the class. The constant f/4 aperture keeps exposure consistent while zooming, and the 80-200mm range suits portraits, travel, field sports and general telephoto work on film SLRs or adapted digital bodies.
These zooms are common and inexpensive on the used market, so condition should decide the purchase. Check the one-touch collar for zoom creep when pointed up or down, confirm the aperture blades snap cleanly with no oil, and inspect both cells for haze and fungus, which telephoto zooms of this age often develop. Verify the mount version matches your camera; bayonet versions adapt readily to mirrorless with a plain adapter.