I finished a film last week, about nine minutes long. In Vegas Pro 9, I rendered it to a master .avi file, in Vegas, using the Cineform codec.

In a new project, I decided I would try using First Light to do a final color treatment to the film. But some scenes I wanted to add one look, while on others I wanted to use another. So on the new time line, I broke up the file in 15 individual scenes by splitting file on the time line. Then for each scene, I rendered 15 successive files in Cineform .avi files again. The render created 15 separate files. During the render process, Vegas showed a screen indicating there was a message that rerendering not required, but a separate file for each scene was rendered out.

Next, I opened FirstLight, brought all 15 files in. I highlighted one scene, and picked look and the color file changes, correspondingly. I then went to next file, which I wanted to give a different treatment. I selected another look. Eventually, as I go through files, I think I am selecting out for each one. No, I was wrong, whatever change I made to one of the 15, was made to the rest.

Can someone explain why that happens ?

You need to turn of the smart rendering in Vegas as all you did was split the source file. The original frames still point to the same database entries. Every CineForm frame has a GUID - global unique identifier, only a full render will change that. Or the can use CFRepair on your new files, it had a switch to generate a new GUID.

Thanks Dave, that answers a whole lot of question in one fell swoop...