Because rangefinder design eliminates the large, bulky mirror box of SLR design, lenses can be designed simply and rear elements can easily recess towards the film plane. The result is the possibility of ideal lens designs, which Mamiya's computer-aided optical R&D department crafts with the utmost pride and unsurpassed precision of any medium format system. The extreme accuracy of rangefinder focusing and lack of shutter or mirror vibration also contributes to razor sharp results not obtainable with SLR lenses. The Mamiya 50mm f/4 is a true wide angle design that produces superb results. The 50mm f/4 opens up a new world of distortion-free ultra-wide angle photography.Applications include reportage, landscape, architecture and industrial photography. Equivalent to 25mm in 35mm format.