The Moy & Bastie has a wonderful movement known as "Drunken Screw". Most cameras had around a 160º shutter angle. The difference of just a few  degrees in the shutter meant a lot to a cameraman when the ASA of film was around 5. Mechanically it was very difficult to get a machine to move the film one frame and return for the next frame within the shutter shaft rotation of 180º. Interestingly, the mechanics of this camera are adapted from the steam engine and the treadle sewing machine.