Sigma's 24-70mm F2.8 IF EX DG HSM is an updated version of this focal length developed in response to the needs of serious photographers asking for hypersonic motor for fast focus response. Also included is the full-time manual over-ride allowing instant control in low-light situations. Whether you're shooting in fast paced situations or low light situations this lens can handle it. Approximately 30% smaller and lighter than its competitors from the major camera manufacturers, it's a dream to handle and carry on your camera all day long. Its price is surprisingly affordable for a top flight professional lens of this caliber. Finally, its outstanding optical formulation makes it a great performer when used for scenic views and landscapes.