OS (optical stabilizer) Minimizes the effects of camera shake for crystal-clear images. HSM (Hyper Sonic Motor) Allows quick, quiet autofocus. Floating internal focusing system helps limit aberration during shooting. EX finish Provides durability and a stylish look. 180mm focal length Accommodates a variety of shooting needs, including wedding and event, portrait, nature and wildlife, specialty and macro photography. 13.7° angle of view For telephoto coverage. 1:1 maximum magnification Produces life-size images. f/22 minimum aperture and f/2.8 maximum aperture For optimal light gathering, resulting in clear, detailed photos. 19 elements in 14 groups with 9 rounded diaphragm blades Create an attractive blur in out-of-focus areas. Three FLD (F Low Dispersion) glass elements help correct color aberration for lifelike hues.