Sigma Corporation is pleased to announce its newly upgraded 17-70mm F2.8-4 DC Macro OS HSM lens. This large aperture standard zoom lens contains state-of-the-art enhancements including the companys own Optical Stabilization (OS) anti-shake technology that offers the use of shutter speeds approximately four stops slower than would otherwise be possible. Once again only Sigma has made it possible for Pentax and Sony shooters to utilize an anti-shake system in either the lens or the camera body.------With a large aperture of F2.8 on the wide end and F4 at the tele end as well as a macro function with a minimum focusing distance of 8.7 inches and a maximum magnification ratio of 1:2.7 this lens is ideal for a wide range of photography. The lens Hyper Sonic Motor (HSM) also ensures a quiet and high speed auto focus while its rounded seven-blade diaphragm creates an attractive blur to the out-of-focus areas to provide the optimal Bokeh effect. The inner focusing system eliminates front lens rotation making the lens particularly suitable for using petal-type lens hood and circular polarizing filters.------Three aspherical lenses and one Extraordinary Low Dispersion (ELD) glass element provide excellent correction for all types of aberrations when shooting with this lens. Additionally the Super Multi-Layer Coating reduces flare and ghosting to produce high-contrast images.