If you’re talking about exporting a movie of the project timeline then I recommend you export in the project’s format with no conversion. Export DV to DV, DVCPro50 to DVCPro50, etc. That way aside from renders, no additional compression will be added in the process. Instead of outputting to tape, I export a QuickTime movie and store it on 1 or more DVD-Roms. For instance on a 30-minute DV/DVCPro project I split the project into two 15-minute segments and store across two DVD’s Later I can transfer back to my RAID and join the two segments. I hope this answers your question.
Lee Berger
http://www.leebergermedia.com