I know you can take a movie thats already gone through Shrink and burnt and do a disc to disc copy. Using a DL disc can you do a disc to disc with a store bought movie ?
You could if you cracked any encryption that was there and if you wanted a true 1.1 copy you would also need to have a DL burner and media. Which isn't as cheap as just shrinking it with Dvd Shrink and burning it to a 4.7 Gb disc. There are all sorts of guides on here and links to other guides about what your interested in, just do a search. Shrink and Dvd Decrypter are both free "and available in the downloads section of this site". Between those 2 proggy's you shouldn't have any problems backing up 99% of the movies you have. Also on a side note, "on the fly" copying like your talking about generaly yeilds more errors than copying/ripping to HDD and burning from there.
On that note, if I may add, most of the DL media I have seen runs anywhere from $10-$15 [bold]PER DISC.[/bold] Our local Wal-Mart had some Verbatim DL media, was like $30 for a 3-pk. Kinda hard to swallow if something goes wrong and you wind up with a pop-can coaster. I'd stick with Shrink and the SL disc's until the price drops.
Yes, you can back up DVDs to DL discs using shrink. Just set target size to 8.5 gb(DVD9) and your set. Depending on what program you use to burn, you can remove the layer break or leave it in. I believe you can remove it if you are using nero since it adds its own break. Hope this helps.
The cheapest I've seen Verbatim DL media is through a seller who has a store on eBay: 3pk $24.50 5pk $36.50 10pk $87.50 18pk $$175.00 Still a lot to swallow! I've invested in a few, but have been very selective in terms of which titles I will use them for. Prob old news to most, but I just read that Verbatim is in the final testing of an 8x DL DVD+R and should be available to consumers near the end of this year. Wonder how much those puppies will retail for?