A photographic film assemblage including a plurality of film units and a dark slide supported in a stack within a film cassette such that the dark slide prevents premature exposure of an adjacent film unit in the stack to ambient light during loading of the assemblage into a camera. The film cassette includes an ingress which is adapted to receive a film advancing member during loading of the assemblage into the camera. As the assemblage enters the camera, the film advancing member progressively and simultaneously moves the dark slide out of the film cassette via an egress therein. The film cassette includes means cooperable with the camera for preventing premature withdrawal of the assemblage during such loading.