to roll 24 or not roll 24?

[Philip Perkins]

In my experience, "true" 24 fps production is very unusual in the USA, but it does happen. Rolling at 48.048 really requires a conversation with post, as you are really compounding the oddballness of the situation now. We'll do whatever they want regarding sync and TC (that we CAN do), but we assume nothing when it comes to non-standard frame and sample rates.

phil p

[Marc Wielage]

This article by Julian Daboll on Trew Audio's website explains when a 48.048 sampling frequency is useful (mainly for 24p television-based projects that are pulled down). I have worked on exactly one 24.00fps digital project in post, and that was Adam Sandler's Grown Ups (which was a huge hit). So it does happen, though it's rare.

I think the best advice is to have a conversation with the post supervisor, the sound supervisor, and the editor, and make sure they're all on-board with whatever frame rate and timecode rate they specify. And get it in writing (like an email). And ask for a workflow test prior to the first shoot day, to make sure that post can deal with any pull-down, sync, or sample-rate conversion issue.

Me personally, I don't think SRC is the big deal some people believe it to be. Note also that any digital VTR or digital file can be instantly pulled-down from 24.00 to 23.976 (or vice-versa) without any real audio or video artifact. Going from 24 to 25fps for PAL or 50Hz HD is a much bigger issue.

--Marc W.

[Toy Robot]

Thanks so much guys. I'll take your advice, and will make sure any non-standard requests are confirmed in writing prior to the project. Thanks again!

[John Blankenship]

Also, Alex, please note that when converting from 24fps to 23.976, the speed is pulled down .1% (one-tenth-of-one-percent), not .01% (one-hundredth-of-one-percent) as you have stated a couple of times ("...must be pulled down .01% for NTSC release anyway...).

[Toy Robot]

Also, Alex, please note that when converting from 24fps to 23.976, the speed is pulled down .1% (one-tenth-of-one-percent), not .01% (one-hundredth-of-one-percent) as you have stated a couple of times ("...must be pulled down .01% for NTSC release anyway...).

My mistake, I'll update it in the post. Thanks!

[chris_bollard]

After being stung on a Varicam shoot where I asked the assist editor , went to the camera test, shot a bunch if tests, sent them off to post. Got the edit ass to look at the test rushes and received an all clear and good to go.

Shot the series, six weeks, went on holiday (from Aust to US) AND then got a call from the line producer wanting to know what was wrong with the sound rushes. Luckily JW group helped me sort it out.

Guess I'm saying don't rely on the word of the cam ass and a test u put together on your laptop. Get the post guys (editor or post sup) for the show to look at it AND ok it. Once it's in the cutting room and you're gone there's lots of time for the blame game to be played out.

[Mark Orusa]

Video shot at 24FPS or 30FPS must be converted to 23.976 or 29.97 to be compatible with common US televisions and broadcasts. Most domestic blu-ray releases are also 23.976, even if they are advertised as 24.

Sound for video shot at 24 or 30 can be recorded a couple of different ways. You can roll at 24 or 30 if it will be coupled with picture before being converted to 29.97 or 23.976. Or you can roll at 29.97 or 23.976 and 48.048 sample rate. The latter assumes the picture edit software will playback and output sound at 48k (as Final Cut does) thus applying a 0.1% pulldown. In either case you should have a conversation with the folks in post first.

BTW, NTSC refers specifically to standard definition 29.97 material. 23.976 HD material is not NTSC.

Mark O

[Jim Gilchrist]

Part of the confusion here (if there is any) is that Panasonic routinely refers to a 59.94 system frequency as 60, 29.97 frames as 30 and 23.98 frames as 24 in their manuals, often making little distinction between images electronically pulled down to 23.98 in a 29.97 fps framework and true 23.98 fps when that frame rate possible on their various platforms.

Best regards,

Jim