The Canon EF 100mm F2.8 lens is a medium telephoto lens with a macro feature for 1x magnification. Fluctuations in spherical aberrations caused by focusing are suppressed, and high-quality images are obtained at all focusing distances. With eight aperture blades, good background blur is obtained even when the aperture is decreased by one or two stops. A focusing limiter which limits the magnification to 0.25x is built-in.