I see so it's the same as with movies...

now if one of the cameras goes out do I have to pretty much let the camera be out until I have an opportunity to recue everything again or can I turn it back on and find another way to synch it in post?

When you're shooting musicians playing musical instruments, you have scores of opportunities to sync picture and sound!

like Jay said , you've got lots of opportunities to sync. Just reload the tape or battery and restart recording. you can pick up the next cue from the song ie: first cymbal hit in that verse.....smashing the guitar on the amp...beginning of the acordian riff , yelling CUT CUT right in the middle ; ) ,...you know what I mean.Lots of cues for the other tapes that will help you line it up in post.
Best bet I would say though is keep an eye on your tape length. you should have some time between songs in order to change out the tape if you think it could run out before the end of the song or set.
Id ratehr have 5 tapes with nothing on the last 3-5 mins on them than 4 tapes that run out and poss lose a great shot from that cams angle.

There are other ways including using a stopwatch, if you do a search Vic Milt had a neat way to do it. But it should be pretty simple

> When you're shooting musicians playing musical instruments, you have scores of opportunities to sync picture and sound!

I understand what you're saying but don't you think it's a little hard to synch that stuff. I mean music is so repetitive, both the musical instruments and the vocals, you might synch a drum thump or whatever in the wrong part of the song? you're back to square one I think; you might as well not synch from the first place ;)

but I guess it's still possible to synch; it'll just be a little harder...

No, it's not all that hard. Sync up a drum hit, scrub to the end and see if you're still in sync. Takes all of a few seconds.

Another technique I've used at times is to zoom in on the audio tracks so you can see the "signature print," which should be very distinctive, and match the two "graphically". Yes, the cameras will be recording two different images, but the sound they're recording will be the same.

As Jay says this is dead easy, cymbal hits would have to be the easiet to sync to. Also the waveform signature from each audio track makes it easy to find sync roughly and then find a really fast spike like a cymbal hit to get it spot on.

Be aware that you'll quite likely get some drift in the audio. Not all cameras record at exactly 48KHz and the audio recorder can also be a few ppm off. But again this is easy to deal with by triming during the breaks between songs. If it's a 60 minute non stop event the you can adjust the timing of the audio with ctl-drag.

Bob.

> Another technique I've used at times is to zoom in on the audio tracks so you can see the "signature print," which should be very
> distinctive, and match the two "graphically". Yes, the cameras will be recording two different images, but the sound they're recording will
> be the same.

Jay I'm not sure I understand. If we're recording audio into a separate machine and recording video with the cameras and synching later, which two audio tracks are you comparing graphically then?

Even if we were using the audio from the cameras they would be different too, actually; the audio they receive is relative to their locations...

Omar, at various times each of us encounters a problem we can't immediately see our way through, and to someone else here it may seem pretty basic but they help out anyway. That's a great thing about the people here.
However these posts of yours seem like film school stuff and unrelated to a specific project. I wonder whether you've chosen the most appropriate discussion site?
There are a lot of books that you can read to build up your expertise.

Omar,
let's say you had three cameras plus a separate audio source, that's three tracks of vision and four tracks of audio. Out of those 3 are grouped A/V pairs.

You firstly need to decide which one is going to be your 'master'. I'd go for the feed from the desk, hopefully it's contiguous.

Now as you rightly point out each camera will record a different version of the sound and all will be way different to what the desk recorded from mics close to the sound sources. However the waveforms will still show you useful info, the loud parts are still loud, the soft parts soft. But the keys are sounds with fast attack, such as symbols hits, claps, coughs and in speech plosives. All these appear as sharp pulses in the waveforms. Yes the acoustics will make the decay waveforms look quite different so you use the leading part of the waveform as the sync marker.

You said you're recording this in a studio so you have some control over all aspects. For real easy sync before the band starts a number insist the drummer gives you a few cymbal hits, get all cameras to shoot the drummer, keep the cameras rolling while they line up the intro shot and THEN let the band start the number, piece of cake to sync the three cameras visually and the wild audio track using the waveform.

To get a better view of multiple tracks of vision also don't forget the track mute and solo PLUS the composite level control, works a treat if all cameras have the same thing in shot. Just be aware on fast movement you can have a 1/2 frame error that you have to live with.

I've done this with just a piano player, no cymbals, so I had him clap, piece of cake in post. Actually I got him so well trained he keeps doing it even when he's playing a real gig.

There's no one shoe fits all answer to this, the best advice I could give is don't freak out, try a few approaches.
Oh and one other. DON'T EDIT ANYTHING until you have EVERYTHING in sync. The follow is real belt and braces stuff but if you've got guys starting and stopping cameras and changing tapes it could really save the day time wise.
Once you've got everything in sync render each camera and the audio track out to a new avi file i.e. solo each camera track and render to an avi, do the same for the audio only, mute all the vision tracks so you get just black as the vision.

Bring those into a new project. Now everything has matching time code, you can hack away at it to your hearts content and the timecode in each track will tell you if you're still in sync. This is the poors mans way of getting to the same point as those with broadcast gear would have with genlocked kit.

And yes, as Serena said do some research and do some experimenting.

Bob.

What Bob and Serena said.

Sometimes I don't splain things too good.

"Waveform signature", that's what I meant to say, but it was 11pm. I should have known better than to try to reply to anyone's post!

Thanks Bob, Jay, for your very insightful explanations!
I always come to this group because of how serious the members are about these forums, and discussing all aspects related to Vegas.

I have the same sync problem shooting theater productions. My house feed from the stage leads my camera mics by a fraction of a second. My solution is to feed the house sound into one channel of each camera, and the on-camera mic into the other. The on-cam track is just a backup while the house sound is in perfect sync with all cameras.