The Sigma 18-50mm f/2.8-4.5 DC OS HSM is a lens dedicated to digital SLR cameras with APS-C size image sensors, offering a large aperture and Sigma's Optical Stabilization and providing a high level of optical performance.
The combination of the large f/2.8 maximum aperture and anti-shake function makes capturing exceptional photos of still subjects in very low light quite achievable, and the wide 18mm focal length is well suited for indoor photography with digital SLR cameras. This lens offers superior peripheral brightness as well as a relatively compact, light construction. Two SLD (Special Low Dispersion) glass elements and three aspherical lens elements provide excellent correction for all types of aberrations. The Sigma Super Multi-Layer Coating reduces flare and ghosting.
Designed with inner focusing and inner zooming systems, high image quality is assured throughout the entire zoom range along with an easy time handling the lens. This lens' minimum focusing distance of 11.8" (30cm) throughout the entire zoom range and maximum magnification ratio of 1:4.1 are quite impressive against their class competition.
Note! Vignetting will occur if the lens is used with digital cameras with image sensors larger than APS-C size or 35mm SLR cameras.