Abstract: A rotary shutter for a motion picture camera consists of two sector blades which are rotatable about the same shaft. The angular relative position of one sector blade to the other is fixed to have a fixed open angle thereby when a smaller open angle is desired. When a larger open angle is desired, one sector blade is fixed in the camera at a position to open an exposure aperture and only other blade is rotated. One sector blade is selectively engaged with the other sector blade or fixed in the camera by axial movement thereof.