Sigma’s 17-50mm F2.8 EX DC OS HSM large-aperture standard zoom lens covers a focal length from 17mm wide angle and offers a large aperture of F2.8 throughout the entire zoom range, making it ideal for many types of photography especially portraiture and landscapes.
Values are for Sigma SA-mount. * DC lenses have an image circle that covers APS-C size image sensors. Not for use on digital cameras having image sensors larger than APS-C size or on 35mm or APS film cameras, as vignetting will occur. The angle of view varies depending on which camera the lens is mounted on. To find the 35mm camera-equivalent focal length, multiply the DC lens focal length by the crop factor (digital multiplier) of 1.5, 1.6, or 1.7, depending on the brand of DSLR camera on which the lens will be used. To find which DC lens is equivalent to a full-frame lens, divide the focal length of the full frame lens by the same crop factor. * Sony A-mount is not incorporated with OS function.