Richard Prosser wrote: > I guess running a 24 fps movie at 25fps would not cause too much of a > problem, but for 60Hz systems I don't think 30fps would be acceptable > - apart from anything else, the sound would noticably increase in pitch 60 Hz is exactly 2.5 times 24 fps, so they use a system called "2/3 pulldown", where one movie frame is shown for two field times and the next is shown for 3 field times. Scan converter chips (e.g., for large progressive-scanned displays) actually know how to detect this so that they can avoid generating some really horrible artifacts when movies are shown on TV. -- Dave Tweed -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist