User Guide

62 Chapter 4 Working With 24p and Variable Frame Rate Video
Currently, there are several techniques for recording 24p video on another format:
 24p recorded at 29.97 fps (NTSC-compatible—in this case, the actual frame rate
is 23.98 fps)
 24p recorded at 25 fps (PAL-compatible)
 24p recorded at 60 or 59.94 fps (720p or 1080p DVCPRO HD; ProHD)
 24p recorded at 48 fps (1080p Sony CineAlta)
Some of these techniques are based on existing film-to-video telecine methods, and
some are newer approaches. In all cases, the video signal is digital, and can contain
embedded duplicate frame metadata (also referred to as flags). When redundant
(repeated) fields or frames are recorded, they are flagged so they can be removed by a
frame rate converter. Final Cut Pro has the ability to remove these redundant frames, so,
for example, 29.97 fps video can be easily converted to 23.98 fps. Another advantage of
24p video is that it has a lower data rate than 25, 29.97, and 59.94 fps formats.
∏ Tip: When you shoot video at 24 fps, you need to avoid quick pans and tilts because they
may cause the image to stutter. This is common knowledge for film cinematographers,
but videographers new to 24 fps videography may not always be aware of this fact.
Film, 24p Video, and Cinema Tools
Cinema Tools is used mainly to edit movies shot and finished on film. To make editing
cheaper and more convenient, NTSC or PAL telecine transfers are used as intermediate
editing formats. Cinema Tools can remove 3:2 pulldown from a 29.97 fps telecined video,
or convert 25 fps telecined video back to 24 fps so you can edit at the proper frame rate
of 24 fps. However, this chapter focuses on 24p footage that originated on video, not film.
For more information, see the documentation that came with Cinema Tools.
24 or 23.98 fps?
Although the term 24p implies 24 frames per second, the value 24 is usually inaccurate,
since most people working within NTSC standards actually shoot at a frame rate of
23.98 fps. On the other hand, 24 fps footage transferred to PAL is truly 24 fps.
While it may be easier to simply say 24p, keep in mind that in some cases, such as
during audio post-production, it’s critical to know the exact frame rate, or your audio
may drift from the picture.