a camera comprising a film winder rotatable in a film winding direction for winding an exposed filmstrip into a film cassette , and a closing mechanism movable to a final position to close a light lock of the film cassette and able to be reset to a starting position to be used again , is characterized in that the film winder is rotatable in a reverse direction which is opposite to the film winding direction , and a resetting device coupled with the film winder resets the closing mechanism from its final position to its starting position when the film winder is rotated in the reverse direction .