Abstract: A device for mounting over the lens of a camera to enable two exposures to be made on film normally available for a single exposure. The device includes a ring section mountable over the lens which merges with a section having an outer terminal end divided into two angularly disposed planes normal to the horizontal centerline of the device and forming upper and lower flange portions. The outermost apex of the flange portions mounts a light-blocking plate adapted for movement from one side of the angularly disposed planes to the other and plate handles which interlock with the flange portions to retain them in place in one position or another and a sighting line on the upper and lower faces of the device.