1hr take: class 4 cards OK, h4 audio sync drifts

Is it possible the camera could detect a slower card and lower the bitrate of the recording to compensate. Meaning, it would still work but you could get better quality with a faster card?
 
J Davis said:
I used CTRL click on the tiime line counter to convert to frames and it was 117215 frames long. 10 frames out means the .wav should have been 117205 frames long and if you divide it out it comes to %99.991468 ... blah blah
Click to expand...

It's probably jitter rather than a pulldown issue (which would have resulted in a much higher discrepancy). a 10 frame difference over an hour is not bad for such cheap equipment...OK, that's 100 parts per million which is high in the pro world but when you consider it as an 00.01% error and which is fixable in < 30 seconds in software, that's quite acceptable.

If you have Adobe Audition, then you can easily make a script to do this and just run it as a batch process on all your audio recorded from the Zoom.
 
I am new to high end cameras, but I am a programmer, and it seems to me, if the camera were able to record video to the card at all, any issue with the sound sync would be the fault of the camera's recording code not the card itself.
 
My gut feeling is the fault is with the H4 zoom not the camera. Until someone does a long sync test with the GH1 vs a DAT or something we won't know.
 
I'm not sure why a sync drift between two unsynced devices should be considered surprising. Unless there is a sync connection between them, each will be using their own clocks and those clocks will not be the same. Close, hopefully, but not the same.

FWIW I just put the audio from an Edirol R-44 to 20 mins of GH1 1080 footage (classical music live performance) and I felt no need to adjust the end having aligned the beginning. There would appear to be no gross clock error in the GH1, so you should get no gross drift vs any other device which has no gross clock error. But you are very likely to get a small error, which of course will be more evident with very long recordings, and will be more obvious with some recordings than others depending on visual content.
 
My test was with the sharp 'clap' sound from a slate. Makes a nice audio peak to line up with.
If you get a chance Ozpeter, can you do a long silent test with a slate clap at each end?
If yours lines up then we know its the H4 zoom that is at fault.
 
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