To maintain high optical performance from infinity to close-up 1:1 (life-size) macro photos without accessories, the new Sigma 50mm f2.8 EX incorporates a "floating" element focusing system. Designed as a quick-focusing macro lens the AF speed of 50mm, f2.8 EX Macro is 1.4 times faster than previous 50mm f2.8 macros. It features a non-rotating front lens group which makes it easier to work with polarizing filters and has a focus limiter (eg. Full Range; - 9.8 in.; 9.1 in. - 7.4 in.). The Sigma 50mm f/2.8 EX Macro lens also features the new deluxe EX external finish. A handy screw type metal sunshade makes it easier to rotate a polarizing filter.