Sigma 310101 50mm F1.4 EX DG HSM For Canon This is a large aperture prime lens with a standard focal length of 50mm, ideal for all digital SLR cameras. This lens has superior peripheral brightness even at the maximum aperture and corrects a possible sagittal coma flare. This lens is perfectly suited for a wide range of subjects enabling outstanding, sharply defined images against a nicely blurred background. The fast, F1.4 aperture makes this lens desirable for use with Digital SLR cameras. This lens effectively becomes an 80mm medium telephoto lens on digital cameras with APS-C size image sensors. The optimum optical design and molded glass aspherical lens elements provide excellent correction for all types of aberrations. The super multi-layer lens coating reduces flare and ghosting. Superior optical performance is also ensured throughout the focusing range. This lens has a minimum focusing distance of 45cm (17.7") and has maximum magnification of 1:7.4. It creates a very attractive blur, even when a small aperture is used. This lens incorporates HSM (Hyper Sonic Motor), which ensures a quiet and high-speed AF as well as full-time manual focus override.