1289538 Film transport mechanism AGFA GEVAERT AG 29 Sept 1969 [28 Sept 1968] 47797/69 Heading G2A A roll film camera has a feeler movable from an inoperative position to an operative position in which it engages a metering perforation in the film at the same time as it locks the film transport mechanism, and has further means which, when the camera release is operated, disengages the feeler from the perforation and holds it thus long enough to prevent it re-entering the same perforation. As shown, the feeler 8b is formed on a lever 8 which has a spring arm 8a bearing against a fixed stop 10. The lever is thus urged in a clockwise direction, so that feeler 8b bears against the film 4 and will engage in a perforation 4a, as in Fig.2. As it does so, an arm 8c oflever 8 engages a ratchet wheel 6 secured to the take-up spool 5, so blocking further film transport. When the release 7 is operated, an oblique surface 7a thereof engages a further arm 8d of lever 8 and pivots it counter-clockwise against spring arm 8a, thus disengaging feeler 8b from the film perforation and arm 8c from the ratchet wheel 6, so that further film transport can now be made, Fig.1 (not shown). A further lever 11 is freely pivoted on lever 8, and has a downwardly extending arm 11a slightly longer than feeler 8b, Lever 11 has a straight edge 11b which, when the mechanism is in the position of Fig.1 (not shown) locates against a fixed member 12b, so holding it with arm 11a downwards. Thus when the release 7 is liberated feeler 8b cannot re-enter the same perforation 4a, because arm 11a is resting against the film. When the film is wound on, arm 11a drops into the perforation 4a, and is carried along by it, until it is rotated out of the perforation by the engagement of straight edge 11b with an inclined part 12a of member 11b. Feeler 8b is now free to engage in the next perforation as soon as it comes into register. Fig. 3 (not shown) is a modification with an alternative means of performing the function of lever 11.