I have been experimenting over the last few days with workflows for both Pro and Movie Studio. First, I made a YUV clip. From that I made lossless test clips (using various codecs) with Avisynth â some that had been converted to RGB with studio levels and some that had been converted to RGB with computer RGB levels.
I fed each clip in turn into Vegas, applied various project settings, and tried rendering them out to the same codec. I compared the rendered clips to the original RGB test clips using an RGB parade and (after converting back to YV12 properly) a Y' wave form monitor.
The results were all absolutely identical frame-for-frame to the original clips. It didn't matter whether the project was set to 32-bit or 8-bit, whether computer or studio RGB was input, whether I used Movie Studio or Pro, or whether the gamma was 2.222 or 1.000 â as long as I converted back to YUV properly after rendering. Apart from basic dissolves, I haven't tested the effects yet, but it seems that some codecs, including lagarith, are passed through without the levels being affected, regardless of whether or not they expect computer RGB.
In my opinion, the dark output that some editors have experienced has little or nothing to do with the compositing gamma. It's more likely a result of people's not keeping track of levels during their workflow e.g. editing in computer RGB and rendering to a delivery format without applying a levels adjustment. The result would be crushed blacks and blown-out whites. (I've seen this in a number of DVDs made by people rendering to MPEG-2 in Vegas and not rendering out a lossless AVI first.)
Glenn Chan says the effects in Vegas ought to look fine in computer RGB with a compositing gamma of 2.222. In fact, he recommends using a gamma of 2.222 on his site, partly because, with 1.000, the effects don't work in the same way and partly because the color corrector does not behave normally. It's nice to have the greater precision of 32-bit in Pro, but I'm not sure how much difference it really makes because Vegas does not have a full linear workflow with color management.
As I see it, unless one absolutely has to have linear light processing for dissolves or 32-bit precision one can safely edit in Movie Studio without needing Pro.