quality loss in backing up my DVD collection?

[Noek]

I was just curious, as I backup my DVD collection using DVDShrink, I was under the impression that a normal retail DVD is a double density disc holding up to 8gb of video. So I suppose during the DVD Copying process using DVDShrink, is there some sort of compression loss of quality that goes on to fit it onto one disc? If so, is it extremely slight? Thanks, sorry for the n00b question

[dafreak]

some commercial disks are dvd-9 (dual layered) and some are dvd-5 (single layered). the latter is the same type that we use to burn movies, etc on.

when you compress an entire dvd-9 disk to dvd-5, then yes you're going to lose quality during the compression. But dvd's come with a lot of extras, different audio streams, and subtitles. Most people here will eliminate the audio streams, subs or extras that they don't want or need in order to get the best quality/least amount of compression to fit onto a dvd-5 disk.