Mamiya's apochromatic RZ67 tele — the electronic leaf-shutter APO-Sekor Z 210mm f/4.5 for 6x7.
The Mamiya APO-Sekor Z 210mm f/4.5 is an apochromatic telephoto lens for the Mamiya RZ67 medium-format system, introduced around 1988. The APO prefix marks it as an apochromatically corrected design aimed at reducing chromatic aberration, setting it apart from the standard Z telephotos. On the 6x7 frame it delivers a longer telephoto reach.
This is a manual-focus lens native to the Mamiya RZ67 bayonet mount, with a focal length of 210mm and a maximum aperture of f/4.5. It contains an electronically timed leaf shutter controlled by the RZ67 body, with the aperture set on the barrel and focusing by the camera bellows. The apochromatic design targets tighter control of colour fringing across the 6x7 frame.
At 210mm on 6x7 the perspective corresponds to roughly a 103-105mm lens on 35mm, a medium telephoto with useful compression for portraits and distant detail. The apochromatic correction helps keep high-contrast edges clean, which is valuable for demanding studio and reproduction work. The electronic leaf shutter allows flash sync at all speeds.
The APO-Sekor Z 210mm f/4.5 is a higher-specification lens and generally commands more than the standard Z telephotos. Because its leaf shutter is electronic, confirm correct firing at all speeds on a working body and watch for erratic timing. Inspect the glass for haze and fungus, confirm the aperture is dry, and verify the bayonet and electrical shutter coupling before buying.