The Sigma 150mm f/2.8 EX DG OS HSM APO Macro Lens (For Nikon) is a super compact and lightweight large aperture telephoto lens, with life-size (1:1) macro capability. To maintain high optical performance from infinity to close-up 1:1 macro photos without accessories, this 150mm lens incorporates a "Floating Internal Focusing" (FIF) system. As a result, the lens also features a non-rotating front lens group which makes it easier to work with polarizing filters. The HSM feature provides ultra quiet high-speed autofocusing as well as full-time manual focus override. Optical image stabilization (OS) allows you to use shutter speeds 4 stops slower than would be possible without OS. The improved DG lens design corrects for various aberrations, using 3 Special Low Dispersion (SLD) glass elements. This macro lens is specially coated to get the best color balance while cutting down on ghosting caused by reflections from the digital image sensor. The lens provides the utmost correction against lateral chromatic aberration which is a serious problem for digital SLR cameras. Close focus capability of 15" (38 cm), with 1:1 magnification. Three Special Low Dispersion (SLD) glass elements control various color aberrations and assure high image quality. Offers Sigma's OS System (Optical Stabilization) allowing handheld photography even in low-light situations. Hyper Sonic Motor HSM provides ultra quiet high-speed autofocusing as well as full-time manual focus override. 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 to about 225mm with most cameras.