Characterized by its versatile zoom range and bright design, the Canon EF-mount 17-50mm f/2.8 EX DC OS HSM from Sigma covers a wide-angle to portrait-length range and features a constant f/2.8 maximum aperture to excel in available light conditions. The optical design incorporates a pair of low dispersion elements along with a trio of aspherical elements to reduce a variety of aberrations and promote greater sharpness and clarity. A Super Multi-Layer Coating is also used to suppress flare and ghosting for improved contrast and color accuracy. Benefitting the optics, a Hyper Sonic Motor affords quick and quiet autofocus performance while an Optical Stabilizer minimizes the appearance of camera shake for sharper handheld shooting. Additionally, the lens is distinguished by its sleek profile, making it an ideal lens for walkaround and travel shooting.