optimum compression settings.

[Guest]

Can someone please list out the best settings for compressing movies from different sources?

1. DVD to two CDs.
2. DVD to one CD.
3. SVCD.
4. VCD.
5. VHS.

(one CD being 600 to 700MB)

I'm asking this because I have seen several cases where a transfer from say VHS (poor quality) is taking up as much space as one made from DVD (much better quality). Obviously this is a waste/ overkill. A VCD should result in a smaller file than a DVD without losing any resolution, since a VCD's resolution is much lower than that of a DVD in the first place.