The Sigma 70-200mm f/2.8 EX DG APO OS HSM for EF Mount incorporates Sigma's OS (Optical Stabilizer) anti-shake system, making it the second generation of large-aperture telephoto zoom lenses with this feature. The Sigma 70-200mm f/2.8 EX DG APO OS HSM for EF Mount offers the equivalent of shooting at shutter speeds 3 to 4 stops slower than without OS, which allows for handheld telephoto zoom shooting even in poorly lit conditions. The Sigma 70-200mm f/2.8 EX DG APO OS HSM for EF Mount's 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.