present-day films are usually run through a camera or projector at a frame rate (running speed or camera speed) of 24 fps (frames per second); older films, made at 18 fps, appear jerky and sped-up when played back at 24 fps - this technique is referred to as undercranking; overcrankingrefers to changing the frame rate (i.e., shooting at 48 or 96 fps), thereby producing slow-motion action when viewed at 24 fps.