Apple Final Cut Pro 7 - Manual (Page 1653)

Conforming 25 fps Video to 24 fps
In countries that use PAL video, film is sped up by four percent (from 24 to 25 fps) and
then transferred to PAL video. You can capture and edit the PAL footage and then deliver
a 25 fps EDL (instead of a traditional cut list) to the negative cutter, who matches the
25 fps timecode back to the original film edge codes.
However, one of the problems with the method described above is that the original audio
is four percent slower than the PAL video containing the sped-up film footage, so you
can’t match the audio to your video in Final Cut Pro. To avoid this problem, you can use
the Conform 25 to 24 command to slow your PAL video footage back to 24 fps. Unlike
reverse telecine, which must actually remove fields or frames of video, the Conform 25
to 24 command simply slows the duration of each frame by four percent so that the
footage plays back more slowly at the film’s original 24 fps rate.
To conform a 25 fps clip to 24 fps in Final Cut Pro
1 In the Browser, select one or more clips you want to conform from 25 fps to 24 fps.
2 Choose Tools > Conform 25 to 24.
The clips are conformed to 24 fps.
If any of the selected clips are not 25 fps, a warning appears stating that one or more
clips will not be processed.
Important: Conforming a clip modifies the original media file. If you need to undo the
conform process, you must use the Conform feature in Cinema Tools. Additionally, you
must have read-and-write privileges for the media files you want to conform.
About 24 @ 25 Timecode
Conforming 25 fps video to 24 fps does not alter the 25 fps timecode of your PAL footage,
so this command creates an unusual media format in which the video rate is 24 fps (the
original rate of the film) and the timecode rate is 25 fps (the original timecode numbers
from your PAL videotape). When you conform 25 fps media files to 24 fps, the media file
timecode rate is defined as 24 @ 25. You can verify the timecode rate for a clip in the TC
Rate Browser column or in the Item Properties window.
24 @ 25 timecode makes it easy to work at 24 fps but retain 25 fps timecode throughout
your edit. You can then export a 25 fps EDL that matches your PAL video footage and
therefore can be matched by a negative cutter to the original film edge code.
Note: Because the editing timebase and playback are based on 24 fps, the 25 fps timecode
no longer accurately represents the true passage of time. For example, 38 seconds of
video (as defined by its 25 fps-based timecode) will actually take 40 seconds to play.
1653 Chapter 99 Working with Film and Cinema Tools