With an angle of view of 33 degrees, this lens is equivalent to a 73mm focal length in 35mm format. Pinpoint sharpness with manual focusing is confirmed from infinity to 1:1 magnification with a green diode in the 645AFD III/II viewfinder. This lens provides a flattering perspective suitable for tight portraits, and permits good working distances in or out of the studio. It can be used for anything from extreme detailed close-ups to full-length portraits. The lens is manually focused (MF) and utilizes focus confirmation in the Mamiya 645AFD III and 645AFD II bodies plus auto-diaphragm operation. Anomalous dispersion optical glass is employed to reduce chromatic aberrations, which results in APO-quality lens performance when focused from infinity to 1:2 magnification, and significantly reduces chromatic aberration from 1:2 to 1:1 magnification. The optical engineering and multi-coatings of this lens achieve excellent color balance, high contrast and high resolution over the entire focusing range, which is an extraordinary accomplishment for a Macro lens. The barrel design reduces flare significantly. Mamiya uses eco-glass, which contains no lead or arsenic, maintaining the company’s "Earth-friendly, Nature-friendly" policy. The Sekor MF 120mm f/4 D utilizes a 16 bit CPU that allows easy firmware upgrading, finer lens characteristic correction and faster, more reliable communication between the lens, camera body and digital back.