Specifically designed for digital SLR cameras equipped with APS-C size image sensors, the Sigma 10mm f/2.8 EX DC HSM Fisheye Lens is a lens that captures a full-frame 167? view in all directions (when mounted on Canon SLR camera). The diagonal field of view of this fisheye lens produces striking images with exaggerated perspective and distortion. The minimum focusing distance of 5.3inch (13.5 cm) and maximum magnification 1:3.3 allows subjects to be as close as 0.7inch (1.8 cm) from the lens' front element. This close focusing capability allows close-up photography and also it is possible to make use of large depth of field that covers wide range of subjects. Even the most familiar and mundane of subjects can be portrayed with startlingly fresh new expressions through exaggerated perspectives and unusual distortion effects. Well suited for academic and technical measurements such as solid angle measurements, cloud cover measurements virtual reality. DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is made to match the smaller dimensions used for the image sensor on digital cameras. As a result, these lenses are also more compact and lightweight, and are better matched to digital SLR cameras. Note: Not suitable for 35mm film SLR cameras, or for 35mm size full-frame digital cameras, e.g. Canon 1Ds or Kodak Pro SLR/c. Features: Fast, ultra-wideangle full-frame lens. EX lens series denotes excellence of engineering and new technology. The HSM (Hyper Sonic Motor) system ensures quiet and high-speed auto focusing with full time manual focus override. The built-in lens hood blocks out extraneous light, and the Super Multi-Layer Coating minimizes flare and ghosting, creating superior image quality. A gelatin filter holder at the rear of the lens allows for the use of gelatin filters.