Just a little add on,
this is assuming you are not rendering to another codec like Mpeg2 and then editing the Mpeg file and then rendering that.

Well, if you went back and fixed the problem in the original project then you could do that until hell freezes over without any effect on quality.
If you work on the rendered output each time then only the bits you make changes to are renderd, the rest is just copied. Now for those bits there will be a generational loss however tests have shown even after 99 rerenders ther quality loss is hard to see. If your corrections are only straight cuts then there's absolutely no loss.

To amplify farss' initial point, you probably should be making the changes to the original project rather than starting over again with the output file. In this case each render is an original render and each new output file is still a 1st generation.

Another advantage to making the changes to the original project is traceability. You are always working from the source so you never get to a point where you want to replicate an effect you got once and can't remember/didn't save all the intermediate steps you took to get there. With one project in Vegas, everything done to transform the source to the final is right there in the project.

The only downside I think with this workflow is that you are re-rendering all the filters every time, so render times might get a bit high. But I'll take it, as I don't think there's anything more frustrating in any creative endeavor(far beyond just video) than finally getting the perfect result and realizing that you have no idea how to ever recreate it.

-Jayson

In DV, if you simply digitize and do cuts only, then spit back to tape no loss will occur. If you manipulate ANY DV file with dissolves, wipes, etc., there is always some loss.

So the no loss theory is flawed if you manipulate. But, the good news is, the Sony DV codec is so good the loss is minimal. There are other DV codecs out there that tear the hell out of the file after rendering.

I can tell that the people in this thread have been doing this a long time, 'cause most of you immediately assumed that the original poster is dealing with DV. ;-) He doesn't mention what format his original video is, nor what he's rendering to, editing, and re-rendering to. It very well could be MPEG.

Rob