24P in Post

Anthony Schilling · June 8, 2005

On an upcoming music project, I'll be mixing some 24P DV with film. It will be my first time mixing the two. When I work with film in NLE, it runs at 29.97 fps with 24fps pulldown. Does 24P video go through a pulldown? My biggest concern is that they will be sharing the same audio track.

Phil Rhodes · June 8, 2005

Hi,

> Does 24P video go through a pulldown

Yeah. Well, it'd have to, wouldn't it?

Depending on the camera settings, it either gets treated the same way as film, or, optionally, with an alternate pulldown cadence which is easier to unwind back to true 24p, but doesn't look as nice if you aren't going to do that.

Phil

Anthony Schilling · June 9, 2005

Hmm, well I convert the audio to 24fps running speed, and it matches up nice with film that is actually running at 29.97. Sony Vegas 6 will capture and is compatable with 24P.. Maybe I can just keep it in true 24P? what is the usual chain for 24P?

David Cox · June 9, 2005

Hmm, well I convert the audio to 24fps running speed, and it matches up nice with film that is actually running at 29.97. Sony Vegas 6 will capture and is compatable with 24P.. Maybe I can just keep it in true 24P? what is the usual chain for 24P?

<{POST_SNAPBACK}>

Well 24P and SD video are a bit of a contradiction. Strictly speaking, there is no such thing as a 24P standard definition video format - at least one that has a supporting tape format. Where this mix has come from is that some DV cameras have a "24P" setting, that captures 24 pictures per second, inserts a 3:2 pull down and so records a standard NTSC (60i) video recoding. So in terms of video standards, its just NTSC but in terms of asthetic look, it has a similar appearance of motion to film since 24 frames are captured each second rather than 60 fields.

So thats why it will match your film in terms of sync, because they have effectively taken a similar route.

In terms of what you do with it, well as I mentioned, "true" 24P can only exist in a non linear environment, on a HD 24P tape format or on film because there isn't a "24P" SD video recorder as such. So to export out to tape or standard DVD, you would have to re-insert the 3:2 pull down to make a standard NTSC output. Thats something you can do right at the end though and may be handled by your system automatically. Keeping your project 24P throughout will reduce the amount of data and therefore processing time you are dealing with as you work. You will only need a true 24P final master if you are sending your output to film.

Anthony Schilling · June 10, 2005

I'll be shooting with a couple of DVX100's as backup to S-8 and 16mm. The new version of Vegas (haven't upgraded yet) will allow me to capture 24P, but don't know yet how it will work in NLE with 24P and film at 29.97 with 24fps pulldown. output will be to digi beta then pressed to DVD.