True Varispeed frame rates?

[Kevin Richards]

Are varispeed frame rates, when set in the camera, such as 22fps, actually 22fps? Or are they, similar to how 24fps is actually 23.976, a slightly different number? When trying to speed up audio to get it to sync with 22fps footage in Avid MC (as some of these action scenes have dialogue mixed in), we've applied what one would think is the correct percentage: 109% (23.976/22=1.089818181818182), but the audio still drifts quite a bit.

By trying different figures it seems 109.03% speed increase brings the audio very close to perfect sync. That leads me to believe the the 22fps varispeed frame rate is actually closer to 21.990 (by using a bit of algebra to solve for X... 23.976/X=109.03%).

If varispeed frame rates aren't actual round numbers, maybe there exists a chart showing what the actual frame rates are for different common varispeed frame rates? I've tried searching for this information high and low, but I can't find it. It's a fairly common practice in action films to shoot at 22fps, as I understand it, to give action a little more kick (no pun intended), so I can't imagine I am the first person to stumble across this issue?

I have to admit I've never operated a RED and am clueless as to whether the camera itself shows you the true frame rate on it's display when using varispeed.

 

[Matthew Quinn]

You can dial in exact frame rates. And also set the camera to record true 24 fps with audio if you so desire

 

[Kevin Richards]

Thanks for the reply. I looked up a tutorial for the menu system in the RED and I see that you can indeed dial in any number you wish. When I look at the clip's metadata in RedCineX I see just straight 22fps. Which leaves me wondering why the percentage to speed up the audio to match the picture is off. The camera was shooting is project timebase of 23.976 and the shooting framerate was 22fps... the project in Avid Media Composer matches the project framerate of the RED setting. The audio was recorded on a SoundDevices 663 48kHz sample rate, broadcast wav files. I just don't understand why the math in my OP is off.

I am also wondering if there is a way to get the camera's metadata showing project timebase and shooting framerate to export in the sidecar files and in to the Avid so they can be displayed in a column in the bins. At the moment I have to refer back to RedCineX every time I want to check the record framerate of a clip.