Editing the material is going to be a major challenge. I don't know whether you will get help from more knowledgeable people than me, but this roughly how I would do it. I suppose that the audio performance was recorded using a multi-track system.
- first, I would decide what will be going my "main camera" for the major takes and note the position of the actors on screen on these takes
- then, I would mix the audio so that the actors position on that camera is consistent with the mix
- then, I would color correct the footage from all cameras so that they look similar (it is a standard function on most editors). I would also de-noise and correct contrast at that point. You may want to crush the blacks a bit to hide the cameras' noise.
- then I would edit the 3 performances separately (on that part, see below)
- finaly, I would cut from the 3 edited performances
For the actual editing, depending on your editor and computer, you have two choices: you can synchronize all takes to the soundtrack and edit in multicamera mode. This is easier, but you'll need a very powerful computer and hard disks for 5 cameras in HD. You'll also need to choose the right codec: too compressed and your processor won't be able to decompress 5 streams in parallel, easier to decode and the 5 files will be too big to stream from your hard disks. The other choice is to keep the files unsynchronized, but it is much more work.
A caveat: don't forget to mix your audio to 48 KHz. Software makes it appear that other frequencies should work, but they never stay synchronized.
All these being said, I would not edit the full show, but make a digest of it, keeping the best arias for example. This should be far enough work already and my experience has shown that the artists prefer a digest, because the main use for them will be a promo DVD.
Thanks so much Jerome. I was planning to do exactly that. I have one genuine professional video camera with uninterrupted recording for each of the the final performances. These are the ones that the others will be synched to using Plural Eyes. Then I'll replace that sound track with the separately recorded sound mix.
What you've told me that's new is to use 48 KHZ and to use position to get the sound right. Well doesn't that require more than the feed from the individual singer? The orchestra has a number of mikes, but the singers just one. They can be anywhere in a giant space/