Japanese company Sigma has announced the 50-120mm f/2.8 DC OS Contemporary, an APS-C telephoto zoom lens for Sony E, Fujifilm X, and Canon RF mounts. The lens completes what Sigma describes as a three-lens APS-C Contemporary zoom system, joining the 10-18mm f/2.8 DC DN and the 18-50mm f/2.8 DC DN — the combined weight of all three lenses is under one kilogram, a figure Sigma presents as a key differentiator from comparable APS-C zoom sets.

The 50-120mm produces a 75-180mm equivalent field of view on APS-C sensors, covering the telephoto range that the 18-50mm leaves unaddressed. The optical construction uses one FLD glass element, three SLD glass elements, and four aspherical elements, arranged to control aberrations across the zoom range from center to edge. Sigma states the design also minimizes focus breathing, which is relevant for video use. Autofocus is driven by a High-response Linear Actuator motor, and the optical stabilization system uses an OS2 algorithm, rated at 6.5 stops at the wide end and 4.5 stops at the telephoto end.

Physically, the lens measures 99mm in length and weighs 390 grams — compact for its aperture and focal range. The barrel is dust- and splash-resistant with a water- and oil-repellent front coating. Compared to previous Sigma Contemporary lenses, the interface has been simplified: both the focus mode switch and the OS switch have been removed from the barrel, leaving only the zoom and focus rings as physical controls.