OT: Sound and SMPTE

DrLumen wrote on 10/5/2005, 7:15 PM

I am curious how some of you deal with multiple video and sound sources (mics). What type of equipment do you all use for recording? If you are going to have several (more than 2) cameras and/or mics, what is the best way to set these up so they can be easily edited/synced?

I was thinking about getting a mixer and some type of SMPTE system but I don't really know if that is necessary and what type of equipment is needed.

Any help would be appreciated!

Comments

johnmeyer wrote on 10/5/2005, 7:30 PM

A lot of people these days are operating open loop (i.e., no central timebase). They then sync on the timeline using a clapboard or simple finding an audio signature on the timeline that matches up. Most digital equipment has a pretty decent timebase, so drift over short timeframes (15-30 minutes) isn't too bad.

I'm sure the pros on this board will have better advice, but for me (I operate in the lower end of the spectrum) I get by just fine without slaving everything together.

B.Verlik wrote on 10/5/2005, 8:12 PM

I've had little problems keeping things sync'd for up to two hours. Ironically, I insist on using one of the SMPTE timecodes, even though nothing is encoded to SMPTE. (and, apparently, I'm the only nut that does this.) This stemmed from the first time I tried to Sound with sound record new audio to an existing video track and I played music with the track and on playback, the audio was not only out of sync but I couldn't simply drag the track back in position because it lasted a different time than when recorded. For me, simply switching the timecode, in project settings, to SMPTE 29.97, and rerecording those add on tracks, solved the problem. (project properties, likes to switch back to "Time & Frames" when you add audio tracks. forewarning)
New problems arised, when I started chopping sections out of very long video pieces. For some reason the sync wouldn't hold if the video was still over an hour, and I could never figure out exactly what happens when this happens. Sometimes the sync started slipping at about the 20 minute mark and only on the render, not in the timeline. On these long recordings that need to have sections chopped out, I now will render out 15 minute mpg2s and stitch them together to avoid having to re-do later. I've also tried rendering a new audio track, to go with the edited video, and then rendering the entire thing and this worked too. (this is not related to the top paragraph)
I think, you just need to experiment for a while and realize that weird things happen from time to time, but for the most part you should be able to count on Vegas to do the job right. (like all software, it doesn't work right until you tweak it to your system and get used to it.)
PS: in case it matters, I'm still on Vegas 4.0e