Case in point, remember how the wheels on the stagecoaches on the old cowboy movies used to look like they were turning backwards. With a little effort, you could probably create a similar effect using the fan or the airplane propellor in the Alice gallery by carefully adjusting the rotational speed of the fan or the prop relative to the frame rate. Of course, here we have even a third parameter to deal with, which is the scan rate on the screen.

Dick Baldwin