Sigma 70-210mm f/3.5-4.5 — manual-focus one-touch telephoto zoom sold across many 1980s SLR mounts.
Sigma's 70-210mm f/3.5-4.5 was part of the company's push-pull telephoto zoom range that filled independent-brand shelves through the 1980s, sold as an affordable alternative to costlier own-brand tele zooms from the major SLR makers of the era.
The lens covers 70-210mm with a one-touch push-pull zoom and focus action, a built-in macro switch near the 210mm end for close-up work, and multi-coated optics housed in an all-metal, all-manual barrel. Sigma produced it in numerous fittings, including M42, Pentax K, Canon FD, Nikon F, Minolta MD, Olympus OM, Konica AR and Contax/Yashica mounts.
Wide open the modest f/3.5-4.5 speed limits low-light use, and corner sharpness softens at the long end, but the macro switch adds close-focus reach unusual for a budget zoom of its time, useful for casual flower or detail shots.
Copies turn up cheaply on the UK used market bundled with old film bodies. Worth checking the push-pull action for grit and slop, the macro switch for smooth engagement, and the front element for haze given decades of storage.