The Sigma 70-200mm f/2.8 EX DG APO OS HSM for Sigma is the second generation of large-aperture telephoto zoom lenses incorporating Sigma's OS (Optical Stabilizer) anti-shake system. It offers the equivalent of shooting at shutter speeds 3 to 4 stops slower than without OS, thus allowing handheld telephoto zoom shooting even in poorly lit conditions. Its HSM ensures quiet and high speed AF as well as full-time manual focusing.,,,It features a large maximum aperture of f/2.8 that remains constant throughout the zoom range, making it incredibly valuable when shooting in low light situations such as wedding or other events. It is also great when shooting fast-moving subjects such as sports, when fast shutter speeds are needed to capture fleeting moments. The 70-200mm f/2.8 is fast and versatile and at a length of 7.8" will be a tool that seldom sees the inside of your camera bag. The lens comes with a petal-type lens hood plus an adapter to extend its length for users with APS-C cameras.,,Note: Optical Stabilizer (OS) function will not work with film SLR cameras except Canon EOS-1V,When using the OS function of the lens with a camera which incorporates a stabilizer unit, please turn the camera's stabilizer unit off,,This lens is optimized for full-frame Canon DSLRs and may also be used with smaller APS-C-size sensors where it will have an equivalent focal length of 112-320mm.,Sigma's New APO 70-200mm F2.8 EX DG OS HSM is the second generation of this large aperture telephoto zoom lens now incorporating Sigma's Optical Stabilization (OS) anti-shake system. It uses two sensors inside the lens to detect vertical and horizontal movement of the camera. It works by moving an optical image stabilizing lens group, to effectively compensate for camera shake.,Two FLD ("F" Low Dispersion) glass elements, which have the performance equal to expensive fluorite glass, and three SLD (Special Low Dispersion) glass elements, combine to provide excellent reduction of aberrations and image quality.,The rounded 9 blade diaphragm creates an attractive blur to the out of focus images (bokeh).,Sigma has managed to make the lens more compact than its predecessor, measuring only 7.8" in length.,The Super Multi-Layer lens coating reduces flare ghosting and assures high image quality throughout the entire zoom range.,The exterior of this lens is EX-finished to denote the superior build and optical quality, and to enhance its appearance.,The lens DG designation translates to large-aperture lenses with wide angles and short minimum focusing distances. With an abundance of peripheral illumination, they are ideal lenses for Digital SLR Cameras while retaining suitability for traditional 35mm SLRs.