Bizarre audio question??

Chamber005

Chamber005

Carbonite Member
So, I can't be the first person to ever try this, but I can't seem to locate the answer I'm looking for.

I have an older professional camera (DSR200) that's no longer able to be used as a viable camera for several different reasons. It still records just fine and has an XLR 3-pin interface, etc.

What I'm wanting to do is to use something like an HV30 or HF200 for visual and use the busted camera for audio and then synch them in post.

So I was wondering, if, for instance, I used the HV30 at 24p, and the DSR records at 30p, how exactly could I go about synching it? Or, more to the point, would I need to worry about synching it if there are going to be multiple cuts? Like, from my understanding when you record 30p audio and place it against 24p video, you eventually have something that goes out of synch -- eventually.

Is that true? Would the average person not be able to notice the synching issue if the frames/recording were essentially restarted every 20-30 seconds?

Hopefully this question isn't too bizarre or ill-informed.

Thanks so much for your help!!!
 
It depends on how long the take is...if its a few minutes at a time there shouldn't be any issue. But keep in mind that whether footage is recorded at 24p, 30p, 60p, the audio is still based off of 16-bit 48 khz... Though the new cameras compress it in some mpg flavor. If you want to sync just use a clapper to make it easier. If there is any time variance it depends on how good the clock is between the two recording devices. I had a similar issue recording 1 hour + long events. I had a microtrack plugged into the board and the cameras just recorded room audio. When I tried to align, they'd go out of sync in about 20 or so minutes. So I got a better recording device with a better internal clock and now its not an issue. It should take longer than 20-30 seconds to go out of sync but you should probably test to be sure.
 
First you have to realize that there are only two speeds (not counting PAL) and that is film speed and video speed. Neither 24P and 30P are "true" descriptions, they are marketing names because they don't think people can handle fractions. "24P" (99.99% of the time, there is one or two rare exceptions) is in fact 23.976P and "30P" is in fact 29.97P. Both are NTSC video speed.

However being tape based they will a certain amount of drift, that is what you have noticed probably. If you pull the audio off analog (or digital) in real time from the tape then you should have no sync problem. If your camera is recording at the normal "24P" you should be able to pull it in as a video clip and use only the audio and not have drift. If your camera is one of the very rare ones that is shooting a true 24 fps then you need to bring it in the first way or your footage and audio will get pulled down to video speed when you put it in a 29.97 or 23.976 timeline.

That said this is a generally bad idea. Cameras are not great recorders, your likely to have to pull the "footage' in to strip off the audio and that is a huge waste of bandwidth and HD space. And camcorders are not all that quiet so doubling the number on the set is not the best choice.

But you have it so it's free, sort of.
 
Noiz2 said:
First you have to realize that there are only two speeds (not counting PAL) and that is film speed and video speed. Neither 24P and 30P are "true" descriptions, they are marketing names because they don't think people can handle fractions. "24P" (99.99% of the time, there is one or two rare exceptions) is in fact 23.976P and "30P" is in fact 29.97P. Both are NTSC video speed.

However being tape based they will a certain amount of drift, that is what you have noticed probably. If you pull the audio off analog (or digital) in real time from the tape then you should have no sync problem. If your camera is recording at the normal "24P" you should be able to pull it in as a video clip and use only the audio and not have drift. If your camera is one of the very rare ones that is shooting a true 24 fps then you need to bring it in the first way or your footage and audio will get pulled down to video speed when you put it in a 29.97 or 23.976 timeline.

That said this is a generally bad idea. Cameras are not great recorders, your likely to have to pull the "footage' in to strip off the audio and that is a huge waste of bandwidth and HD space. And camcorders are not all that quiet so doubling the number on the set is not the best choice.

But you have it so it's free, sort of.
Click to expand...

True, they're not great recorders, but the audio I get from my (once upon a time 6,000 dollar camera) with XLR inputs even after its audio being "stripped" is still lightyears better than the audio I get from the HD camcorder we're using.

And I get you about the fps. It sounds like so long as we don't have takes that go on and on we should be okay with synching, whether we go 30 or 24. And, honestly, the cam we're using records everything in 60i regardless, so we'll just have to see if the 24p mode is worth any possible future headaches.
 
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