The Sigma 50-150mm f/2.8 APO DC D EX HSM lens is a stunning efficient telephoto zoom lens that allows you to get close to the action. The Sigma 50-150mm f/2.8 APO DC D EX HSM is designed for APS-C sensor DSLRs. The HSM provides a quiet, faster autofocusing and allows the option for full manual focus override. The APO feature of the lens creates the highest quality images by a specially designed low-dispersion glass to minimize color irregularity. Four SLD glass elements help eliminate chromatic aberrations while providing superb image quality throughout the zoom range. Super Mulit Coating on the glass minimizes flare and ghosting and ensures high contrast images. The nine blade diaphragm gives a pleasant caliber to the out-of-focus areas of your photos.