The Sigma lens for canon has both automatic and manual focus options for the serious photographer. It magnifies up to 7x. This Sigma OS camera lens has a Hyper Sonic Motor (HSM), so all autofocus actions will be quick and quiet. As a 125 mm camera lens, it has an effective focal length of 200 mm. This Sigma lens for canon is known in photography circles as an excellent value that provides strong sharpness and contrast. This Sigma OS camera lens has Defocus Control (DC). The Defocus Control provides the photographer with some control over how elements in the image that are out of the range of focus will appear. The manufacturer made this 125 mm camera lens from Special Low Dispersion (SLD) glass, which reduces chromatic aberration, preventing "fringes" of certain colors from appearing in photos. It has an Inner Focusing System, which does away with front lens rotation for those interested in using certain kinds of polarizing filters. At just 3.5 inches long, the photographer can pack this Sigma lens for canon for any trip.