Sigma 17-70mm f/2.8-4 DC Macro OS HSM Lens. This standard zoom lens is designed exclusively for digital SLR cameras and incorporates Sigma`s original OS function. This lens covers several angles of view, from wide to telephoto as well as offering a large aperture of F2.8 at the 17mm focal length. It provides a bright image through the viewfinder and enables photographers to easily check focusing and composition. The lens has a minimum focusing distance of 22cm and a maximum magnification ratio of 1:2.7 making it ideal for close-up photography as well as landscape and macro photography. ELD (Extraordinary Low Dispersion) glass and aspherical lenses provide excellent correction for all types of aberrations and high image quality is assured throughout the entire zoom range. Super Multi-Layer Coating reduces flare and ghosting. The incorporation of HSM (Hyper Sonic Motor) ensures quiet and high speed AF.