Canon 5D Mk II Clap-Board Audio Sync Issue

[Sabreena Pe]

Hey,
I’m having a huge issue with syncing sound that I recorded with a Zoom audio recorder and a 5D. I can sync the guide track and the audio together at the beginning, but there is a drift so that by the end of the clip the recorder audio is abotu half a second off from the guide track. I’ve tried the easy setup fix, and have tried converting the video to prores, and have had no luck. Any suggestions?

[Joel Ninmann]

What model Zoom recorder did you use? The H4N? What frame rate did you shoot the video on the 5D Mk II at? 24 fps (actually 23.976 with firmware version 2.0.4) or 30 fps (actually 29.97 with firmware version 2.0.4)? What firmware version is installed in your 5D? What editing software and version are you using (Final Cut Pro X, Final Cut Pro 7, Adobe After Effects, Avid)?

Generally the quick solution (without getting into why) is to set your audio down to a speed of 99.9%. Try that.

Joel Ninmann
Instructional Specialist
Department of Communication Arts
University of Wisconsin-Madison

[Sabreena Pe]

Hey Joel,

We used the H4 model of the Zoom recorder, and we shot at 24 (23.98 fps). I’m editing with Final Cut 7. I’m not totally sure what firmware is on the 5D,. but I’m guessing that it’s 2.0.4 since FCP shows the framerate as 23.98fps.

I have tried changing my audio speed, but without success.

I’ve uploaded one of the files I’m working with if you want to try taking a look at the elements (I figure it’s easier to troubleshoot when you have access to the file)

you can find the guide track here: https://f1.creativecow.net/3578/guide-track

The AIF version of the track, converted to 48 kHz is here: https://f1.creativecow.net/3580/recorded-audio-aif-version

The WAV version of the track at 48 kHz is here: https://f1.creativecow.net/3579/recorded-audio-original

Let me know if you’re able to figure anything out, because I just can’t seem to.

Thanks

[Sabreena Pe]

I have an update to share, but still am trying to figure this out. I realized that the audio recorded on the zoom recorder is at 44.1 kHz, and the audio for the 5D footage is at 48 kHz. Now I have tried converting the audio to 48 kHz through FCP and through compressor, but it didn’t seem to work. I actually pulled the supposedly converted track into FCP and compared it with the original 44.1 version and they matched up with each other, so it doesn’t seem that the sample rate is actually being changed. The interesting thing, however, is that I when I tried converting the clip from the 5D to 44.1 kHz, (converting the guide track to match the recorded audio versus converting the audio to match the guide track) everything ended up syncing up. I feel like converting all the video I have though will end up taking way longer and take up more space, and just intuitively feels wrong. I feel like there has to be a solution somewhere to get the recorded audio in sync with the audio from the 5D, I just can’t totally figure out how to get the clip to up-convert properly, so that it actually runs at 48 kHz. Any ideas?

[Bill Simonett]

Update- if you are using adobe cc auto synch, your synch
Will be 1-2 frames out with the 5d. Just be wary and always check your synch!

[Scott Robert]

I know the post is a bit old but this odd behavior still exists. I’m editing RED footage and audio was recorded into the camera. (Same issues with other cameras as well) I have to sync the audio to match how the camera records it which is 1-2 frames before the visual slate hits. So in other words, looking/listening at the video footage, I place a marker and in mark where I hear the slate which is before the slate impacts. Plural eyes match by audio’s visual waveforms and should sync perfectly.

I don’t understand the science behind that as I was always trained to sync right where the slate closed. It doesn’t seem to be the case anymore.

[Bryce Douglass]

I’m not using the same camera referenced in this topic but I can for sure tell you that my canon xa20 and canon xa10 do the same thing unless I switch the frame rate to 1/30.

Bryce