The Mamiya 43mm f/4.5 is a true wide angle design that produces unparalleled results - with a maximum of 0.04% distortion at the corners. The 43mm f/4.5 opens up a new world of distortion-free ultra-wide angle photography. Supplied with ultra-wide optical finder. The detachable ultra-wide optical finder is used for composition. It features a built-in, adjustable diopter, rubber eyecup, and built-in spirit level..