Sampling rate for double-system external audio recorder

[Stephen Pruitt]

I'm running my REDs at 23.976. I'm using an SD788T with the framerate set to 23.976, but my choices for sampling rate are five:

47.952 (which would, in the absence of better info, make sense to me)
47.952kF (with the file stamped as actually having been recorded at 48kHz)
48
48.048
48.048kF (with the file stamped as actually having been recorded at 48kHz)

I'm editing using FCS.

What would YOU select?

Thanks much.

Stephen

 

[Bruce Allen]

I could be totally wrong on this (I'm a director, not an audio guy), but let me try help...

You are editing at 23.976, right? Not 24? Probably finishing to HD tape, with the possibility of going to film from that later on down the line? In that case I'd pick 48khz.

AFAIK:
- you rec audio at 47.952 if you're filming at 23.976 but want to edit at pure 24fps (not 23.976). This way you can speed them both up to edit at pure 24 with no resampling.

- you rec audio at 48.048 if you're filming at 24 and want to edit at 23.976 with audio at pure 48khz. Then you can slow down audio and picture the same amount with no resampling.

Personally I always shoot 23.976 picture / 48khz audio because to me getting to a great 23.976 master with as little confusion as possible is the most important thing. If my audio has to be marginally pitch-shifted up for theatrical playback, so be it.

Other people who care more about the 24fps master being at perfect pitch would pick 47.952 I guess.

Bruce Allen
www.boacinema.com