The Mamiya Sekor AF 150mm f/2.8 IF D is Mamiya’s fastest telephoto lens. The use of low-dispersion glass allows correction of chromatic aberration and produces critically accurate color and high contrast images from infinity to the closest focusing distance. With an angle of view of 26 degrees, the lens is equivalent to a 93mm telephoto lens in the 35mm format. The minimum focusing distance is 3.3 feet, which is 1.8 feet closer than the existing AF 150mm f/3.5 lens. The use of internal focusing (IF) makes the lens extremely well balanced and perfect for hand-held photography. Autofocus and manual focus functions are easily selected with one-touch action; simply move the focusing ring backwards or forwards. With shallow depth of field and close focusing capabilities, it's ideal for portrait photography. The lens is compatible with the Mamiya 645AFD III, 645AFD II and ZD cameras. With the ZD back the equivalent 35mm focal length is 106mm.