23.98 and the Zoom H4N
 

Has anyone had successes/frustrations using the Zoom H4N to capture and sync audio with the 7d? Does shooting at 23.98 cause the audio to go off-sync? I've found forums about the 5DmII and this issue, but not yet about the 7D and 23.98. Any experience/workflows would be appreciated. Thanks!

Get the plural eyes software if you're a Vegas or FCP user. One click and you're synced up. It's only $50 I think. You can get the trial version.

I've seen pluraleyes used with the 5DmII at 30fps (the fix being that the user creates an easy setup for 30fps, rather than 29.97), but I haven't heard anything about people using it or the zoom with 23.98. Any Zoom users out there?

Pluraleyes seems to work fine for me with a 24p timeline and the zoom. Only used it this week so far though. Pluraleyes is $150 it says on their site btw

I just got the Zoom and recorded a test with the 7D at 29.97. Started both, did a clap on cam, ran for 11 minutes, then clapped again 3 times. Imported into FCP and once I synced the first clap, the next 3 were dead on 11 minutes later!

Then at my first shoot this week with on cam audio, we decided last minute to record at 23.97. I did not test this before hand, but it too works fine. I didn't do 11 minute clips, but some of the interview clips were 7-9 minutes and it held sync all the way through.

So for me, there seems to be no problem. Make sure the Zoom is set to record 48k wav files and I think you'll be fine. I'm guessing some of the issues people are having has as much to do with different sample rates then frame rates. But try the simple test I described above on your own with your own settings just to be sure!

Thanks for the replies. I'm assuming since there is a lack of responses here that the H4N is working fine for everyone. I'm going to try it at some point with the highest quality audio and see if that drifts at all.

The sync issues with the H4n & 5D have to do with the 30 fps rate and FCP's handling of imported audio - creating an Easy Setup with a true 30 timebase before creating a project solves the problem entirely. I don't have a 7D to test with but it sounds like the proper framerates resolve this issue.

I came across a YouTube video of a guy running the Zoom with a 7D and he did about a 10 minute test with a slate at the front and end. It was out of sync by the end, but in the video he says the trick is to set the audio timeline duration at 100.042% to make it sync perfectly.

I don't have a Zoom to try it out on, but it makes sense. Can't recall the URL or any other details about this video - sorry.

I saw that clip too, so I tried my own test as stated above. There were no sync issues in my test at all. I don't know what his settings in the timeline were or what his sample rate was for the audio, what he transcoded to, there are lots of areas it could get out of sync. If he transcoded to 30fps, instead of 29.97 it would go out of sync...

Not sure why the different results, but mine came out dead on.

Yes there are lots of variables at work here including each person's individual copy of each piece of gear. The H4N is much better at holding sync than the original H4, but each person should test it with their own gear under similar conditions to the actual project (including temperature which can have a dramatic effect on the timing crystals).
There's still alot of luck of the draw with your individual gear, it's just the new H4N has a smaller range of variance from device to device.

We have tested the Zoom H4n carefully and find it can hold sync to within one video frame for about 100 minutes. It's a wonderful device and we recommend it to anyone wanting to do dual audio with DSLRs.

The FCP speed issue with the 5D (which some people fix with a 99.9% speed change) shows up in a different form for the 7D (which some people fix with a 100.1% speed change). But DON'T do either of those fixes, they will likely just cause problems somewhere else. Instead, just make sure that the frame rate in your Easy Setup matches the frame rate of your video. If you change the Easy Setup, restart Final Cut before making a new sequence. Don't ask why, just do it. And don't think that you can drag your clip to the timeline and have FCP autoconform the sequence and have it work--it doesn't. You have to go via the Easy Setup route.

If you follow that one simple rule you'll have no problems with timing issues with the 5D or the 7D.

There's a blog post and video tutorial that explains all this here: http://brucesharpe.blogspot.com/2009...-solution.html

Bruce Sharpe
Singular Software