Three-two pull down
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Three: Two Pull Down is a term used for Film to Video transfer in the world of film. In North American film, film runs at a standard rate of 24 frames per second. Video runs at a rate of (29.97)30 frames per second. Every video frame has two fields for each film frame. The three:two pull down, is where the telecine adds a third field to every second video frame. You will notice this extra field if you pay attention to detail, while the medium is still in video. When transferred back to film, it seems as though the third field does not exist, but it will bring the rate of 30 fps back to 24 fps for editing purposes. The point is to keep your image and sound in sync.
However the true rate of North American video is .1% slower than 30 fps, due to a colour process that was corrected by slowing the video down. This means that it is actually 29.97 fps. This may not seem like much, but the sync will catch up, and your audio can end up being several seconds out of sync with the image. In order to correct this, you will ask the technician for either a pull up or pull down. A pull up will speed up the sound by .1%, and this is used for transferring your video back into film. A pull down will slow the speed of your audio down by .1%, and this is necessary for transferring video into film.
