For photographers who want an ultra-compact telephoto lens, the Sigma EX DC APO HSM is a practical choice. This Sigma camera lens for Canon offers powerful features in a small, 7.8-inch form that can easily be carried on a strap, or tucked into a camera bag. Hyper Sonic Motor technology provides fast and whisper-quiet autofocusing, making this 50-150 mm f/2.8 lens an excellent option for photographing animals and other sound-sensitive subjects. The Sigma EX DC APO HSM features a rounded, 9-bladed diaphragm, creating an attractive soft blur on out of focus areas of an image. This Sigma camera lens for Canon features 21 elements in 15 groups, coated with Super Multi-Layer Coating to ensure sharpness, contrast, and minimal ghosting or flares. For finely tuned photography, the 50-150 mm f/2.8 lens is also compatible with 77 mm camera filters. The Sigma EX DC APO HSM is also compatible with teleconverters, offering fine photo quality at an even greater range.