rotary shutter which can adjust its shutter angle electronically while shooting. Rotary shutters on still cameras While the vast majority of rotary shutters are naturally used on motion-picture cameras (as well as projectors), there were some still cameras that employed this type of shutter, notably the Univex Mercury rangefinder and the Olympus Pen F SLR. Both of these cameras were half-frame 35mm cameras (frame size 18 x 24 mm). The rotary shutter proved to be very simple to construct, accurate and reliable in these cameras. Though, in the case of the Univex, it resulted in a very strange "hump" on top of the camera to cover the shutter disc. See also Shutter speed Time-lapse – similar issues to shutter angle Photographic shutters