Mamiya's fast APO 645 tele — the AF-era A 150mm f/2.8 APO with apochromatic correction.
The Mamiya A 150mm f/2.8 APO is a fast short-telephoto lens for the Mamiya 645 system, introduced in 1996. The A designation marks it as part of the later autofocus-era Sekor A line that followed the earlier C and N generations. The APO label indicates apochromatic correction aimed at reducing chromatic aberration, setting it apart from the older f/4 telephotos.
This lens is native to the Mamiya 645 bayonet mount, with a focal length of 150mm and a maximum aperture of f/2.8. It was produced for the autofocus 645 bodies of the era while retaining manual focus capability. The apochromatic design targets tighter control of colour fringing at wide apertures, and the f/2.8 speed is a full stop faster than the common 150mm f/4.
At 150mm on 645 the perspective suits portraiture with pleasing compression, and the f/2.8 aperture produces markedly shallow depth of field on the large frame. The apochromatic correction helps keep high-contrast edges clean when shooting wide open, where lesser designs can show colour fringing. This made it a preferred fast telephoto for demanding portrait and studio work on the format.
The A 150mm f/2.8 APO is a later, higher-specification lens and appears less often than the older manual telephotos, usually at a higher price. Inspect the glass for haze, fungus and cleaning marks, confirm the aperture operates cleanly, and check that the autofocus and manual focus mechanisms move smoothly. Test any electronic coupling, verify the mount for wear, and look for coating scratches before buying.