Pull Down is most commonly used when editing audio against a work video that came from a film transfer. The work video runs slower than the film, since film@24fps is transferred to video@30fps, and the color video is then played back at 29.97fps. In general, the user will get work tape audio from DAT or Nagra at 'film' speed. The audio is transferred into the Mac at x1 speed, then pulled down for editing so that it matches the 'slow' video.If the audio is transferred back to the work video, it should be transferred at the pull down rate. If it is going to film (directly, or via DAT or Nagra), it is transferred at x1.