The 135mm Elmarit-R has a reputation for oustanding Sharpness & Contrast, even wide open. At F4 the lens is performing already at its maximum. It is perfect for portraits and for close up photography. Its flat field and ability to work well with the Elpro attachments allows this lens to become a stellar performer, even at 1:3 magnification. It was produced in two versions with two different optical formulas. Both versions utilized 5 elements in 5 groups, but the later version had a completely different optical formula. Another Great Leica lens when you need the extended reach of the 135mm focal length.