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Why can’t PluralEyes sync camera footage with an audio recorder?
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[Dave Haynie] “Once you have three or four that remain in sync, and it’s NOT by design… well, if you’re that lucky, I hope you bought a PowerBall ticket last night :-)”
It must be luck then, as I have mixed and matched camera’s (FX1, NX5, Z1P, C110 and PJ760) and have not come across any audio sync issues. If they are drifting, it is by nanoseconds. One edit/job I did do recently which involved getting an audio feed from a sound desk did have slight sync issues which the sound engineer picked up, but no one else did.
In the days of analog I used to have terrible sync issues, but since going digital with HDV, natter.
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Ditto Nigel,
I have 3 JVC HD7’s, a Sony NEX-VG-10 and mix of Zoom and Tascam pocket recorders and I have never had any drifting problems. The HD7’s record to hard disk and the files are roughly 17 mins long then you have a 2 second audio break between files. Maybe this does not allow them to drift as much. Like John R. I usually either get a feed from the mixing board or set up the recorder in a good spot. The camera mic tracks get synched and mixed together(listening for any phase problems) then I mix that track with the audio recorder track. I will sometimes have to nudge the entire audio recorder track in relation to the camera mic track, but it is not drifting-just more like manual delay compensation. -
I think that’s the other thing — good design. I have mixed camcorder brands, camcorders and HDSLRs, etc. on multi-cam shoots, and never had a problem with video clips walking away from each other.
But this was a problem with audio recorders. That was due to bad design. Seems to mostly be fixed in the latest crop of devices.
-Dave
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[Colin Morris] ” I will sometimes have to nudge the entire audio recorder track in relation to the camera mic track, but it is not drifting-just more like manual delay compensation.”
That’s the synchronization part — the job PluralEyes does for you. That’s normal, and it’s always an issue when you start multiple things at different times. The deal with drift is that you sync at one place, but the recordings “walk away” from one another. Using the worst quality quartz crystal I have ever used on a product (100ppm), that means you really wouldn’t see meaningful sync loss under about 30 minutes.
The great thing about PluralEyes (and similar) is when you have, say, a couple of audio recordings, maybe three camcorders going, each with many clips as they’re moved about, started and stopped, etc. That’s a good bit of work to sync by hand… nicer to just press a button and have it all locked together. When it works, which for me is pretty much always.
I use one digital recorder, usually, for the time base… it runs through the entire event. Both my Tascam D1 and Zoom H4n keep good sync, but it’s pretty well documented that earlier Zooms, like the Zoom H4, had lousy timing. That seems to be on the order of 500ppm, which would imply it’s using a high quality ceramic resonator rather than low quality crystal. The price differences are not much… in quantities of 25K or so, you could pay $0.60 for a 10ppm crystal, $0.40 for a 100ppm crystal, or $0.10 for that ceramic resonator.
The HD7s don’t record seamlessly? That’s a shame, most newer devices don’t drop a bit between 4GB files, though I have yet to find a camcorder or HDSLR fully supporting 64-bit file systems. Once you have SDXC card, the 64-bit exFAT file system is required, even if you’re only dropping 4GB files.
-Dave
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[Dave Haynie] “But this was a problem with audio recorders. That was due to bad design”
Not bad design – just lowest cost design for voice recorders. Most weren’t designed to be synchronized with video, so loose timing specs were acceptable.
Then DSLR’s hit the market. Now there’s a poor design for audio recording.
Steve Mann
MannMade Digital Video
http://www.mmdv.com -
Sure, for voice “dictation” devices, the clock’s not that critical. But I don’t think anyone’s using these for video. The digital field recorders (Zoom, Tascam, Marantz, etc) were designed for audio recording: better-than-CD quality for music, etc.
Sync issues have been known for decades in the digital pro audio world. The fact that some of this kind of device didn’t even try to use accurate clocks IS a design flaw.
-Dave
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The fact that some of this kind of device didn’t even try to use accurate clocks IS a design flaw.
I beg to differ – it is not a design flaw, as it was not designed to sync with video.
The digital field recorders (Zoom, Tascam, Marantz, etc) were designed for audio recording: better-than-CD quality for music, etc.
And they do an excellent job of that – as designed.
Steve Mann
MannMade Digital Video
http://www.mmdv.com -
[Stephen Mann] “I beg to differ – it is not a design flaw, as it was not designed to sync with video.”
Well, as a professional electrical engineer, I still disagree. It’s not that some of these devices were not designed to sync to video (and certainly, while DSLRs are new, pretty much every other kind of video camera pre-dates the advent of high quality digital recorders), it’s that they were not designed to sync. Period. A Zoom H4 can’t be expected to sync with another Zoom H4 any better than your it will your camcorder.
As additional evidence for this being a design flaw, I present exhibit A: camcorders. They pretty much do sync, one to another, without any need (or usually, provision) for a bit-clock input. Not forever, sure, but until SDHC cards, the question was only of staying in sync for 83 minutes or less.
As exhibit B, I present “other digital field recorders”. My first recorder, the very first Tascam D1, has an accurate clock; never had a problem with it syncing with any of my three pro-class camcorders or my 60D, or the Zoom H4n. This came out in early 2008, before any DSLR was on the market…. I used it initially as a field recording adjunct to my Sony MD recorder. The Marantz 660 (wasn’t that the original point), released in 2007, also had good accuracy.
And there’s exhibit C: the MD recorder. These also synched to video just dandy.
No one’s expecting these to sync for 24-hours at a time. But as I pointed out, the difference between the quality of sync of most of these devices, and the few that don’t sync, amounts to about $0.30 per unit. That tells me those who have that problem didn’t understand the problem they were trying to solve, and that has nothing to do with video sync. That makes it a design flaw.
But hey, you’re welcome to disagree, and I won’t yammer on about it anymore.
-Dave
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John
when I do event work and get audio drift on the digital recorder I use Vegas time stetch to sync the ends after I have synced the starts. The Vegas elastique Pro is a very good quality algorithm and slowing down or speeding up the Digital Recorder audio by maybe .01% is totally inaudible but allows easy synchronization
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