A medium telephoto macro lens offering excellent picture quality and close-up magnification up to life size (1:1). Optimizing the optical power distribution reduces spherical aberration fluctuation during close-up photography, delivering constant high picture quality over all focusing distance. The inner focusing system makes the working distance (the distance from the lens to the subject) 149mm during life-size photography - twice the distance of the 50mm macro lens. Convenient operability is achieved with the easy full-time manual focus ideal for subtle adjustments of the focus position (a task in macro photography and the non-rotating front lens element. If the optional ring-type tripod mount B (B) (with an adapter for the EF100mm f/2.8 Macro USM) is used, switching between vertical and horizontal compositions without affecting the optical axis is a simple matter.