Sigma's unique Art-line APS-C telephoto — constant f/1.8 from 50-100mm, like two fast primes in one.
The Sigma 50-100mm f/1.8 DC HSM Art was released approximately 2016 as a constant-aperture telephoto zoom for APS-C DSLR cameras in Sigma's Art line — notable for maintaining f/1.8 across the entire 50-100mm range, a specification not matched by any other telephoto zoom at the time. DC confirms APS-C coverage; HSM provides ultrasonic AF. Sigma SA mount.
f/1.8 constant aperture. 50-100mm zoom range (approximately 75-150mm equivalent on APS-C). DC (APS-C coverage). HSM (Hyper Sonic Motor) for fast, quiet AF. Art line optics. 82mm filter thread. At approximately 1,490g. Sigma SA mount.
The constant f/1.8 across the 50-100mm zoom range is the defining characteristic: no other telephoto zoom for APS-C matches this speed. The 82mm filter thread and ~1,490g weight reflect the large-aperture optics required; this is a physically large lens for an APS-C format. The DC designation means it covers only the APS-C image circle — heavy vignetting on full-frame bodies. Also available in Canon EF-S and Nikon F mounts.
On the used market the Sigma 50-100mm f/1.8 DC HSM Art Sigma SA is an unusual constant-aperture telephoto zoom for APS-C. Condition checks: HSM AF response, 82mm front element for marks, zoom ring smoothness, f/1.8 aperture blade condition. The DC designation limits coverage to APS-C — not for full-frame bodies. Mount options (EF-S, Nikon F, SA) are mechanically distinct; confirm mount before purchase.