Combining a versatile telephoto range with a constant f/2.8 maximum aperture, the Sigma 50-120mm f/2.8 DC OS Contemporary Lens is a compact and portable zoom designed for APS-C cameras. Its 100-240mm-equivalent focal length range is well suited to portraits, travel, everyday telephoto photography, and distant subjects, while fast autofocus, powerful optical stabilization, and a weather-resistant construction make it a dependable choice for both stills and video.
The lens uses Sigma's HLA (High-Response Linear Actuator) autofocus system to quickly and accurately move the focusing group. Its responsive focusing performance supports rapid transitions between subjects and reliable tracking of moving subjects, making it useful for everything from static scenes to active subjects such as children and pets.
Focus breathing is also effectively suppressed, benefiting video creators who need consistent framing when adjusting focus during recording.
Sigma's OS2 optical stabilization algorithm provides up to 6.5 stops of shake compensation at the 50mm position and 4.5 stops at 120mm. This powerful stabilization helps reduce the effects of camera shake for sharper handheld images and makes the lens particularly useful when working in low light or shooting at the longer end of its zoom range.
The optical construction incorporates one FLD element, three SLD elements, and four aspherical elements to control aberrations and distortion while maintaining high sharpness and accurate color reproduction throughout the zoom range. The lens is designed to deliver consistent image quality even when used wide open at its constant f/2.8 maximum aperture.
An 11-blade rounded diaphragm contributes to smooth, attractive bokeh and gradual focus transitions, helping separate subjects from their backgrounds and giving out-of-focus areas a pleasing appearance.
Despite its constant f/2.8 aperture and versatile telephoto range, the lens measures just 3.9 inches in length and weighs under one pound, making it particularly convenient for travel and everyday use.
Dust- and splash-resistant construction provides added confidence when shooting in changing weather conditions, while a water- and oil-repellent coating on the front element helps resist contamination and makes the lens easier to clean.