Editing 24p footage at 29.97

February 18th, 2008

In the past I’ve surveyed the many issues of editing 24p video in a 60i world. A recent comment on that page reminded me that there’s another option that I hadn’t discussed.

Shoot 24p. It looks great. Once you’ve shot it in 24p, you’re never going to lose the “filmic” quality of the motion that you get from shooting progressive frames. Because you can only get interlaced video on a DV tape, what’s on your tape is now interlaced, but it’s interlaced in the same way that The Matrix is interlaced when it’s shown on standard definition TV. It still looks like The Matrix, it doesn’t look like the 11 o’clock news just because it’s interlaced.

Editing in 24p can be tough. If you don’t really understand what you’re doing you can end up causing a lot of unnecessary trouble. So you can edit in regular old 29.97 NTSC. You probably won’t see the difference. The one time I see a problem with footage that was shot 24p but edited at 29.97 is playing on my HDTV. My TV is a progressive scan monitor. It automatically detects 3:2 pulldown and removes it from the video, which results in a nice progressive picture. This works best when the video has a continuous pulldown cadence. A film that is telecined has pulldown added in the same cadence throughout, so once the TV picks up the cadence, its work is done. The same is true for videos shot and edited in 24p. However, a video shot at 24p and edited at 29.97 has a pretty good chance (80% I think) of changing its cadence on every cut. So after every cut I see a few frames of interlaced video before the TV figures out the new cadence.

The good news is, nobody else notices this.

My advice is, if you’re going crazy trying to figure out how to edit 24p video, do yourself a favor and skip it. NTSC 29.97 works just fine.

Entry Filed under: Editing