Rotary disc shutter

When blocking the light, the exposed portion of the film is advanced, and another, pristine frame is moved into position.

Adjusting the shutter angle controls the proportion of time that the film is exposed to light during each frame interval.

Using an exposure time of 1⁄50 second gives a shutter angle value of 173°, very close to 180° (normal motion blur effect).

Previously, this effect could only be achieved by purposefully mis-adjusting the timing belt of the film advance mechanism in the camera.

However, several manufacturers now provide accessories to electronically control the phase relationship of the shutter and film advance mechanisms.

Instead, this adjustment controls the amount of time that the electronic sensor collects light in order to create each successive image.

Because electronic cameras do not need to mechanically advance film, it is possible for the shutter to be open for nearly the entire period of each successive frame.

Though, in the case of the Univex, it resulted in an apparent hump on top of the camera to cover the shutter disc.

When the shutter is open, the film is exposed. When it closes, the next frame of film is brought into position by the claw.
Adjusting the shutter angle affects the amount of time that film is exposed to light.
Rotary shutter in an Agfa Caja 44