A few weeks ago I did a little fact sheet on CDs and the preservation thereof for my preservation and conservation class. For that report I learned about lovely things like CD rot and CD bronzing; now it seems that such things are happening to DVDs as well, and in greater proportion than CDs, even though CDs have been around about a decade longer than DVDs.
According to the Sydney Morning Herald, between one and ten percent of DVDs develop problems which render them unplayable, whether through manufacturing defects or through mishandling. Many manufacturers are refusing to replace DVDs they claim were mishandled. It's hard to tell who's right, since these are such new formats that there's not a lot of information about this sort of problem. Certainly businesses that make money off of CDs and DVDs don't want to shout out By the way, don't be surprised if this $20 piece of plastic-coated aluminum disintegrates in a couple of years.
Probably some of the problems are a result of manufacturing defects, whereas others are caused by mishandling. I think mishandling, in turn, is caused by misperceptions about the strength, resilience, and permanence of optical-disk media. How many times have you bent your CDs or DVDs when pulling them out of their plastic cases? Did you realize that bending them like that can cause them to delaminate? (Delamination is the separation of the plastic layers encasing the aluminum inside; in the presence of oxygen, the aluminum quickly oxidizes, and portions of the disk become unreadable.) I don't think anyone realizes that; besides, CD and DVD cases are often so hard to manage that mistreatment of the CD is almost inevitable.
As for the difference between CDs and DVDs, my theory is that the problems are more perceptible on DVDs. Although both CDs and DVDs have error-correction built in, DVDs hold much more data in the same physical space, and thus the holes and bumps are much smaller, and the potential for data destruction is greater. Also, it's easier to perceive corrupted video data than audio data. But that's just my theory, so I could be wrong.
In any case, I think I'll hold off on buying a DVD player for myself until there's more information about what's causing these problems.
[Link to Sydney Morning Herald article via kuro5hin.org via The Shifted Librarian.]
Post a comment