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 150mm f/4.5 is a moderate telephoto, using a unique design of six elements in five groups, along with low and ultra-low dispersion glass to create apochromatic performance matched to the entire group of Mamiya 7 lenses. Applications include portraiture, fashion, landscape and aerial photography. Equivalent to 71mm in 35mm format.