After being played probably 50 times in one month a DVD would no longer work. I scoffed at my wife’s suggestion that perhaps it work out. I pointed out that only light touched it. Then I began to think of laser surgery and death rays and such, and thought maybe so. Can a DVD wear out?
If handled roughly, yes, but not from the light touching it, I don’t think.
The data layer of a single-sided DVD is stored just under the label, behind a thin layer of lacquer that’s surprisingly easy to mar. Image.
Here are other factors which can “wear out” a DVD.
that’s for a CD. DVDs (even single-sided) have the data layer in the “middle” of the disc due to the different wavelength and focal point of the laser.
Blu-ray discs have the data layer right under the reading surface.
dauerbach, the only “wear out” I’ve ever encountered is “disc rot,” which is where air infiltrates the coating/sealer and starts to oxidize the reflective metal flashing. The reading laser is nowhere near powerful enough to damage a disc.
So you’ve got one of those DVD players that magically levitate the disk when it’s spinning? Or maybe one where the disk doesn’t even spin - it’s the DVD player that spins around the disk!
A DVD-R can be wiped out by sitting in direct sunlight.
A manufactured DVD’s non-reflective bits are non-reflective because the foil has been literally burned through, but a “burned”-at-home DVD-R’s non-reflective bits are non-reflective because there’s a layer of photosensitive dye over the foil, which has been activated by the laser during burning. Direct sunlight can quickly destroy the data - and it will even naturally degrade (slowly) over time, even without being left on your dashboard in August.
When CDs were introduced in the 1980s, one of the major selling points was that, unlike vinyl or tapes, they would never wear out; you could play them as many times as you like with no decrease in sound quality. Later reports indicated that CDs aren’t necessarily that immortal, as Cecil discusses in his column Do CDs have a life expectancy of 10 years? But never, in the decades since they were introduced, have I heard any reports of CDs wearing out from nothing other than being played too many times.
I assume the same would apply to DVDs, both conventional and Blu-ray. I find it interesting that, just ten years ago, Cecil didn’t even think to mention DVDs in his column.
Home CD/DVD/BD players typically support the disc at its outer edge when it’s resting in the tray, and at the hub when it’s pulled into the player; a carefully-handled disc need not ever have anything in physical contact with the region where the data is stored.
Born In The USA, which I bought in 1985, still plays on my CD player; as does a disc of classical piano music. My oldest commercial DVD’s are only about 13 years old, so I guess there’s no way to be sure yet. I remember a scaretactic disc seller aout 15 years ago suggesting that due to oxidation, the lifetime of CD’s was about 10 or 15 years. So far, they are wrong…
DVDs and CDs are gripped by the center hole, the playing surface is never touched in a normal player. Therefore, there is no “wearing out” from contact.
I would also ask if the OP disk is unplayable in all DVD players or just the one. I had a CD back when that would only play about half the time in some players. I think the start of the track was a bit too close to the center hole.
Whether properly stored burnable discs will deteriorate over time? I don’t know, but I have not run up against that problem yet, I think the oldest burnable CD I have is 1995 and I haven’t tried it recently but it still worked a few years ago. I consistently use some discs over 10 years old.
I’d like to point out that this is not correct.
DVDs (as well as CDs) are pressed. The data is encoded in the form of pits that are depressed from the surface. The player uses interferometry to read the disc.
I stand corrected as to that. I think my linked info still has some merit, though.
What? So my CD/DVD writer separates the clear plastic covering of the recordable media, physically pokes holes in the film, and then reassembles the clear plastic sections?
And here I always thought that a laser burned dyes on the film to create contrasting dark spots (not a pit but achieving the same purpose) into the film that was sandwiched between the clear plastic.
I would have guessed that a high intensity light/heat source (like the sun?) would actually have a detrimental effect on a DVD-R if it was exposed for a long time.
Or did you mean to specifically address manufactured DVD’s? OR are you addressing DVD-Rs"
I believe that beowulff is referring to commercially manufactured pre-recorded DVDs and CDs.
Commercial discs are pressed. Homemade discs are burned.
I caution against a blanket statement that CDs, DVDs or whatever will deteriorate in X years, or under Y conditions. There appears to be a wide variability between manufacturers and even batches from the same manufacturer, and this applies to tape as well.
I have some (writable) CDs where the data surface is flaking off, but others of the same age and another manufacturer, kept under identical conditions, that are pristine.
I have some consumer-grade audio recording tapes from the 1950’s that are perfect, playable, and not crumbling, but some of the top-of-the-line tapes from the 1970’s that are so gummed up they cannot be played for more than a minute without oxide piling up on the head. Yet some other tapes of the same year, same manufacturer and model that are just fine. Here it’s a batch difference (and 3M once analyzed my samples and agreed that the batch was substandard when new).
My experience has taught me that you cannot be dogmatic about media longevity and you should not jump to conclusions. Just because you have one 20yo CD that’s bad doesn’t mean they all will be, although I agree that pressed ones are less likely to be affected by light than burned ones.
Not quite in the same vein as the OP, but still relevant IMHO is that some discs (presumably with slight internal physical imperfections) can shatter when spun at very high RPMs. I don’t think these high RPMs are found anywhere other than a CD/DVD writer in a PC though.
ETA: Presumably, older discs would be more proven to be resistant against this.
Thank you for confirming my assertion that CDs/DVDs are actually touched while being played.
Yes, the machine touches them while they are being played, but not in a way that could possibly damage the data-bearing portion of the disc.
Or were you just being pedantic about the definition of “touching the disc?”
I was just being pedantic. If the OP is going to chastize his wife using imprecise language, I thought he should at least be corrected on that point.
Thank you for pointing that out. My belief that the pits were burned into the reflective surface directly comes from a popular science show I saw around 1981, when CDs were still just on the horizon. Reading a little, a see that the process is actually much more interesting.
And now I have something for the “what’s the longest you’ve been wrong about something” thread.
To be fair, the master copy is burned in, but the commercial copies are just that…copies, pressed much like an LP (remember those?).