The wide range of the Sigma APO 150-500mm F5-6.3 DG HSM is perfect for the photographer working at long distances with subjects such as birds or small wildlife. The Sigma 150-500 features three SLD (Special Low Dispersion) glass elements for optimum color correction and sharpness, a rear focusing system which corrects for fluctuation of aberration due to focusing, and Optical Stabilization and high speed Hyper-Sonic Motor to help you take the eye-catching photographs you’re meant to.