Being a macro telephoto lens, the Canon EF 100 mm f/2.8 USM lens brings to life the minutest detail in small subjects such flower petals, insects, etc. The three-group floating system in this f/2.8 USM macro lens lets you capture excellent close-up shots. This Canon 100 mm lens is equipped with a secondary diaphragm that prevents stray light from entering the wide aperture, to give you sufficient contrast in your images. The ultra-sonic monitor (USM) in this Canon 100 mm lens allows superior internal, accurate, and silent auto focus at all focusing distances. The Canon EF 100 mm f/2.8 USM lens also allows excellent manual focus in AF mode. The high quality optics in this f/2.8 USM macro lens allows you to capture life size close-ups without any adapter. The Canon EF 100 mm f/2.8 USM lens can be used as a normal telephoto lens as well.