Thanks to this site, I'm learning about the 'nuances' & complexities of disc burning. And I'd like a little education about disc degradation.
Assuming high quality media is used, how big of an issue is disc degradation? I guess I'll break that question down into some sub-questions:
1) I'm curious about what exactly happens to a disc (CD or DVD) that results in "degradation" over time. I remember when CDs first came out (1982, IIRC?) the consensus was that optical discs could very well last a lifetime or more. You have a metal substrate sealed by a clear plastic coating, and the data is encoded in microscopic patterns burned into the disc surface, so what can "go bad"? The patterns aren't going to move or change shape, are they? And as long as it's not scratched & exposed to air, the substrate won't corrode or oxidize, so .... Again, what goes wrong? (I'm excluding obvious things like subjecting the discs to abuse.)
2) Generally speaking, which are more prone to degradation -- CDs or DVDs? And why?
3) This is kinda related to Question 1, but what goes wrong with a CD to make it "develop" more C1 errors over time? Or develop C2 errors when there weren't any when the disc was originally burned/created?
4) I was a teenager and a huge music fan in the mid-80s when CDs first came out, and to this day, every one of the CDs I bought back then still plays flawlessly. Since they're ~20 years old, how can they still work perfectly if CD degradation is a 'real' issue?
5) Are commercial DVDs more or less prone to degradation than the ones people like us burn on our computer burners? And why?
6) Again assuming high quality media is used, is there any kind of "rule of thumb" amongst experts about how often a person should make fresh copies of their self-burned CDs & DVDs and discard the old ones? Every 2 years? 3 years? 5 years? Or is the answer simply, "Scan them every few months and make new ones as soon as errors start developing"?
Heh heh ... that should make a good start.