The Sigma 17-50mm f 2.8 EX DC OS HSM lens is an image-stabilised, fast wide angle zoom for digital SLR cameras with an APS-C sized sensor. The lens covers a focal length from 17mm wide angle & offers a large aperture of f/2.8 throughout the entire zoom range, making it ideal for many types of photography such as portraiture & landscapes. Alongside Sigma's Optical Stabilizer (offers the use of shutter speeds Approx. 4 stops slower than would otherwise be possible), the 17-50mm OS lens also
Includes:: a hypersonic autofocus motor, for quicker, quieter focusing. It uses two elements made from Sigma's new FLD glass, plus two glass mould & one hybrid aspherical elements, to reduce aberrations & offer excellent image quality. Super Multi-Layer Coating reduces flare & ghost, meaning the Sigma 17-50mm lens has superior peripheral brightness & provides sharp, high contrast images even at the maximum aperture