Sigmas latest All in one walk-about zoom lens with Optical Stabilizer This high zoom ratio lens is designed exclusively for digital SLR cameras and incorporates Sigma’s original OS (Optical Stabiliser) technology. This system offers the use of shutter speeds approximately 4 stops slower. Pentax and Sony mount lenses are also equipped with the OS function as it is possible to use this with camera bodies which already incorporate a built-in anti-shake system. -Four SLD (Special Low Dispersion) glass elements and three aspherical lenses provide excellent correction for all types of aberrations. -High image quality is assured throughout the entire zoom range. -The HSM (Hyper Sonic Motor) ensures fast and quiet auto-focusing. -This lens has a minimum focusing distance of 45cm (17.7in) and a maximum magnification ratio of 1:3.4, making it convenient for close-up photography. Technical Specifications - Lens Construction - 18 Elements in 14 Groups Angle of View (SD Format) - 69.3 - 5.7 degrees Number of Diaphragm Blades - 7 Blades Minimum Aperture - F22 Minimum Focusing Distance - 45cm Maximum Magnification - 1:3.4 Filter Size - 72mm Dimensions - Diameter 79mm x Length 101mm Weight - 630g