dual sound out of sync changes in time

[Steve House]

...
Certainly we have seen occasional reports by people who happen to have a camera and an audio recorder that keep PERFECT sync for hours on end. That is not impossible, but it is very rare, at least IME. And it probably is not repeatable in unusually hot or cold situations, either.

Every time I read one of those claims I suspect that there is something going on in their test setup that is giving them false results. A set of tuned Lockits can do it when used with cameras that accept genlock and recorders that can sync to external wordclock but now we're talking about clocks that cost several orders of magnitude more than the clock components in typical consumer and prosumer gear.

 

[den59]

It is amusing that a new generation of video producers just assume that random pieces of equipment (of whatever quality level) should ipso facto always be in perfect sync. ...

Certainly we have seen occasional reports by people who happen to have a camera and an audio recorder that keep PERFECT sync for hours on end. That is not impossible, but it is very rare, at least IME. And it probably is not repeatable in unusually hot or cold situations, either.

Thanks for your detailed reply. Just wanted to note that i, personally, did not assume that everything will be in sync and I will have perfect result and no problems with rubbish equipment I had to use due to some reasons (for a record, i'm not talking about money making here).
In any case, I learned how to deal with the problem as well as how to avoid it in future.

An on-camera shotgun is not going to be pointed at an off-camera interviewer, thus putting him off-mic for his voice. It would be better to use two lavs, one on each person. One lav goes to left channel, the other to right, and the stereo camera track is split into two mono tracks in post. Not that that has anything to do with sync drift issues.

Thanks for the advice. I will try this in future.