A camera assembly includes an endcap assembly for closing off the bottom end of a second film chamber, which is sized to selectively receive a roll of film or a secondary film cartridge housing a roll of film. The endcap assembly can include a movable shutter blade enclosed between two plates. The endcap assembly can be removably secured to the camera assembly. At least a portion of the endcap assembly can be formed with the camera assembly. Embodiments further relate to a method of loading such cameras, especially in the daylight. The method involves bringing a sleeve into light-tight engagement with the endcap assembly and then inserting a winding rod through the sleeve and the endcap assembly and into a second film chamber of the camera. The winding rod can then be used to wind film out of a cassette in the first chamber and into a roll in the second chamber.