Rotary focal-plane shutter

One unusual design, the Olympus Pen half-frame 35 mm SLR system, manufactured by Olympus in Japan, used a rotary focal-plane shutter mechanism that was extremely simple and elegant in design. This shutter used titanium foil but consisted of one piece of metal with a fixed opening, which allowed electronic flash synchronisation up to and including its maximum speed of 1/500 of a second – rivalling the capabilities of leaf-shutter systems
Another 35 mm camera system that used a rotary shutter,^{[citation needed]} was the Robot Royal cameras, most of which were rangefinder 35 mm cameras. Some of these cameras were full-frame; some were half-frame, and at least one Robot camera produced an unusual square-sized image on the 35 mm frame.
The Mercury II, produced in 1946, also used a rotary shutter. This was a half-frame 35mm camera.