This Sigma 150-500mm f/5-6.3 APO DG HSM Lens is for DSLR cameras with a Pentax K lens mount. It is an ultra-telephoto zoom lens ideal for nature, wildlife, or sports photography. This lens is designed for full-frame cameras and is also compatible with APS-C format DSLRs. The zoom range translates into the approximate focal length equivalence of 225-750mm when used with APS-C cameras. A Hyper Sonic Motor enables fast, smooth and quiet auto focus and its rear focus system prevents focus-dependent variation in aberration, provides quick, convenient manual focus and a non-rotating, non-extending front barrel during focus. Its APO apochromatic design with three Special Low Dispersion glass elements virtually eliminate chromatic aberrations and the DG-system and Super Multi-Layer coated optics reduce flare and ghosting. For such a long telephoto zoom lens, this is a compact and lightweight option with an included rotating tripod collar. It also includes a dedicated lens hood and carrying case. It is compatible with the optional Sigma APO teleconverter. Designed for use with full frame digital SLR cameras. May also be used with smaller APS-C size sensors with a corresponding effective increase in focal length equivalence to about 225 to 750mm with most cameras.The HSM (Hyper Sonic Motor) system ensures quiet and high-speed auto focusing with full time manual focus override.Three Special Low Dispersion (SLD) elements provide excellent correction for chromatic aberration.The improved DG lens design corrects for various aberrations throughout the zoom range.Super Multi Layer (SML) coating reduces ghost and
