The 250mm f/4.5 APO is in the mid-range of Mamiya's 6x7cm format APO series lenses. It utilizes computer-aided design and Mamiya's ultra-low dispersion glass for elimination of chromatic abberation. The extensive use of low dispersion glass makes APO lenses heavier and more costly than standard design telephoto lenses. Typically, lenses over 200mm focal length show decreased sharpness, resolution and color saturation due to increased chromatic aberration, especially at wider apertures. The Mamiya APO Series are specifically designed to give the utmost performance in telephoto design lenses, yielding consistent, unparalleled image quality. No other medium format lens manufacturer offers such as series of APO telephoto lenses, optimized for a wide range of apertures and distances for commercial applications, not just at infinity focus, as are traditional medium format APO designs. Applications include commercial and table top photography, landscape, aerial, wildlife, sports, portrait, beauty, and fashion photography, where ultimate image quality from a long focal length and an image compression effect, is desired. Equivalent to 121mm in 35mm format.