Spot's suggestion is very true, but syncing the cameras clocks is also not a bad idea, you should be able to get them within one second, might help to find your way fairly close and then use the audio sync for fine sync. I think someone some time ago also suggested using a flash gun instead of a clapper board.
If you've got cameras with external TC in some nice gadgets are available to keep them in sync without needing cables or wireless links.

Flash cannot get you more than one-frame accurate.
Clapboard or other hard transient will allow you to be near sample-accurate.
Audio, particularly with Vegas, is always more simple to sync than video because with video, best you're gonna do is half-frame or 1/60th of a second. With audio, you can approach 1/1000th of a second.
If you can't use a clapboard, flash somewhat works in a pinch.
Resetting clocks of all cameras will get you within 1 second or so, but it's not going to assist in the sync, excepting you can right click the media, look at the original TC, and line it up within a second. A hard transient like a hand clap or clapboard will provide a beautiful little spike that will make syncing a breeze.

Unfortunately, I believe vicmilt said he cannot use a clapboard as it is a live stage show. I recently shot a play with two cameras. Without the use of a clapboard, I basically lined up the footage from the two cameras based on other audio cues (loud/distinct sounds, etc.). Once you line it up at one point, it should remain in sync for the rest of the reel. In the case of tape changes, you'll just have to line up the cameras again.

Sorry there's no one-click solution to this, but even with the use of a clapboard, lining up the cameras is still a manual task. It's hardly tedious or difficult by any means tho, so you shouldn't have much problem getting in-sync :)

Here's what I do.
You have to initially sync up the cameras using one of the methods described above.
I do not know how to do this in Vegas. You need to be able to see the clock.
Look at camera 1. scrub until you see the 'second' change. (i.e. time change from hh:MM:01 to hh:mm:02.
Look at camera 2. scrub until you see time change from hh:MM:01 to hh:mm:02.
You can then use the difference between those 2 points to line up your susequent reels.
I hope above makes sense.
I also stagger my camera start times so that all tape changes do not occur at the same time.

You guys will have to tell me if it's just me but I've have problems syncing two video sources up via the audio. The problem mainly comes from having cameras that are placed with different, and sometimes very different distances, to the source. Sound takes longer to travel from the source to one camera or the other. So when you line up the spikes, the video from one camera will appear slightly out of sync with the synced up audio from another. Only only way I've found to fix this is to eyeball the video to audio sync or use a clapperboard and sync to the clap in the video frame.

Has anyone else experienced this?

John

Yes! I had exactly that problem. Someone in here advised the use of flash, so I've used that since and am happy with the results. If you use external mics, I'd be tempted to run the line to the camera furthest away or go wireless.

You guys have inspired me to a great way of syncing - to a pre-mastered set of clocks.

1. Sync all the clocks - to the second.
2. Shoot the clock at each camera start - it's private, quiet and puts you right into the ballpark.

Now - any suggestions??? Clockwise??

They've got to be :
Digital
Large enough to shoot easily with your normal camera, and sittl be able to read the numbers.
Cheap enough to crunch or lose (or have " borrowed").
Cheap enough so that each camera crew has it's own clock.

Thoughts?? Suggestions??

We just shot and synched a 4 camera shoot in a classroom setting, it couldn't have been easier.

It was a stage storytelling show about whaling. We set up 4 camera angles.

Rule #1 once you start rolling, don't stop.
Rule #2 all cams have audio on.
Rule #3 watch for my signal to start tape. There is always one that is not paying attention and that was true here, so within 30 seconds everyone was going.

OK, so now we have 4 separate camera clips captured and loaded on the timeline. I have about a minute of empty timeline space to the left of the clips for maneuvering room.

Now we search for an audio event to synch to. In my case, the talent screamed out "Greetings!!!" which made a very nice waveform that was easily found on all clips.

Simlpy align the first clip to the second zooming in on the timeline fairly far in and tweaking it. (you mute out the other clips for now) And then you listen and watch and voila, in synch.

Then align the second to the third and then third to fourth....

Check work by comparing the fourth track to the first track, all tracks together, etc...

Check down the timeline to see if the tracks are in synch near the end.

I think my demonstration took about 15 minutes, but, I could have easily done the alignment in less than 5 minutes if it were just me.

To me this is a no brainer provided all cams have audio.

If you can make a moderately accurate guess about the distance from the camera to the sound source, then it is fairly easy. Sound travels approximately 1.129 feet per millisecond (it varies depending on altitude, temperature and humidity which determines the density of the air.) In dry air at 21c, which is 70f, sound travels at 1129.5202682997958 feet per second. Divide the distance in feet by 1.129 to come up with the number of milliseconds by which you need to slip the audio. If the camera was 50 feet from the sound source, then you must slip the audio earlier on the timeline by 44 milliseconds, about a frame and a half in NTSC land. You generally want to error on the late side, since we are all used to seeing something before we hear it. If we hear it before we see it, then that really messes with our brains.

John

OK - I just have to ask.

Have you ever put all this to practical use, I mean, do you actually take equipment capable of measuring atmospheric pressure, humidity and density on a shoot?

dvdude,

Well, yes, on occasion, I have. For what it's worth, the speed of sound in air is primarily affected by temperature.

John

Damn, that's one DEDICATED dude. When I was in school, we had to time for reverb stats in various room temps. I did it at the Salt Palace when the ice was down.
But..back to subject.
With an audio spike of any kind, you can easily sync to the sample, whether it's audio from a DAT matching to a cam or using the cam mic hearing the delay, because everything is relative. Delayed audio or not, the cameras all see the same thing at the same time, so syncing in post is very easy by lining up 2 or more spikes. We used to do genlock for everything back when we were SP. It's actually easier visually lining things up. And a lot less hassle.

I did this on a 4-camera shoot (my first multi-camera) last fall. This was of a dance group outdoors. I found it wasn't that difficult to align the audio on identificable sounds - a loud handclap from the audience, a sharp note from the instrument. I then used Excalibur Multi-cam wizard (great tool for this). The problem I had was I found I had to go back and turn on "Quantize" in Vegas, or I had problems with the video on the cuts between cameras. This threw my audio betwen cameras off a bit, but no one but me has noticed (or at least commented on it).

Gary