Mamiya's RZ67 standard lens — the electronic leaf-shutter Sekor Z 90mm f/3.5 W for 6x7.
The Mamiya Sekor Z 90mm f/3.5 W is the standard normal lens for the Mamiya RZ67 medium-format system, introduced with the RZ67 in 1982. It was the lens most commonly supplied with RZ67 bodies and served as the default optic for studio and general 6x7 work. On the format it gives a natural normal field of view.
This is a manual-focus lens native to the Mamiya RZ67 bayonet mount, with a focal length of 90mm and a maximum aperture of f/3.5. 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 design covers the full 6x7 image circle.
At 90mm on 6x7 the perspective corresponds to roughly a 44mm lens on 35mm, close to a true normal view that works for portraits, general shooting and landscape. The electronic leaf shutter integrates with the RZ67's metering and allows flash sync at all speeds, a key studio advantage. The lens delivers even sharpness across the large frame when stopped down.
As the RZ67's standard lens, the Z 90mm f/3.5 W is plentiful and affordable on the used market. 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 engage properly.