DVD's as long-term storage?!?! Think again

[Wayne]

It would seem that the business types have built in obsolescence in the manufacture of DVD's...

http://www.smh.com.au/articles/2003/01/ ... 19345.html

Comments?

[Phoenix '97]

"The failures are a combination of corrosion - known as "DVD rot" - and delamination, where the layers of the disc separate."

I don't see how recordable media would be affected by this, having only one layer.

[cfitz]

I don't see how recordable media would be affected by this, having only one layer.

You are thinking of data layers, but what they mean is physical layers. And DVD recordables do have multiple physical layers (just like CD recordables - laquer, reflective layer, dye layer, polycarbonate substrate) that could be susceptible to delamination if not manufactured well. Also, the organic dye in recordable media can be corrosive to the reflective layer. So, what they descibe is possible for poorly made media.

Hopefully this won't be a real problem. There was a fair amount of concern about this issue in regard to pressed audio CDs some years back. And while the general concern is fair, so far it hasn't worked out to be the disaster that nay-sayers predicted. My oldest audio CDs (15 years old) still play just fine and check out find in CD Doctor. I think part of the fear is a natural backlash to the overblown claims the optical media is indestructible and will last forever. In all likelihood, the truth lies somewhere in the middle.

cfitz

[Solr_Flare]

A lot of this DVD rot that is occuring is probably due in large part to a combination of poor care of discs and/or not enough controls in the manufacture of DVDs. With DVDs becoming so popular so quickly a lot of companies probably sacraficed extra production controls in order to maximize total profits. This can also be seen in some of the cheaper brands of blank DVDs from certain companies where some burners have extreme difficulties reading them because of poor manufacturing...or blanks rated to burn at certain speeds but only half a batch does so. As stuff like this creeps out we will probably see in the long run improvements in the quality and life expectancy of DVDs.

In the meantime, this study is a big boon to companies like DVDXCopy who are currently engaged in battles to prove they serve a necessary and legal need...ensuring that we can make copies of movies that we own so that when stuff like this happens we still have the movie we payed for.

[Pradeep]

Laserdiscs had the same problem. It's believed to be due to dodgy glue which eats away at the aluminium.

[freeloader]

I saw an article somewhere a couple of days ago about this phenomenon. I don't remember exactly where I saw it, but the feeling I came away with was that it wasn't anything to be too overly concerned about. The 3 links below seem to indicate that the problems are with prerecorded DVD movies not with blank media for data storage. Even if you're buying prerecorded movies it seems to be a problem in a small number of instances. I don't buy DVD movies or copy them. Hopefully it will not be a problem for me.

http://www.afterdawn.com/news/archive/1655.cfm

http://www.pnc.com.au/~jmcmanus/dvdrot.htm

http://www.andraste.org/discfault/discfault.htm

[Wayne]

Interesting info guys,

My own _suspicion_ is that this effect is related to the number of times the DVD (and CD's ?) has been illuminated by the laser. Photochemical reactions are easy to induce and predict because the strength of illumination and distance is tightly controlled and the chemistry of the process of data encoding is well understood.


Remembering the crew of the Columbia....

[Phoenix '97]

I don't see how recordable media would be affected by this, having only one layer.

You are thinking of data layers, but what they mean is physical layers.

Ah. Learn something new every day.

[Funkstar]

I had a batch of BASF CD-R disk a few years back that all started to rot away from the edges. Managed to pull most of the data off before they became totaly corrupt.

I would be pretty confident in saying that this would just be down to poor production techniques and not an inherent flaw in the technology.

[erickotto]

A while back had about 6 'printed' DVD movies that couldn't play anymore after only been watched twice. Send the back to WB manufacturing plant after ACC from them. ANd eventhough they did replace them, they kept saying it was user scratches. WHich it wasn't ..

Every once and a while I still find a DVD that can't be played anymore (got over 600). ANd looking at them closely under the right lighting conditions you can see blotches and shades. I am sure it is the substrate glues problems..

my 2cts worth,

Erick

[cfitz]

Every once and a while I still find a DVD that can't be played anymore (got over 600). ANd looking at them closely under the right lighting conditions you can see blotches and shades. I am sure it is the substrate glues problems..

Sounds like it might be. Do you keep your DVDs in an air conditioned environment? I wonder if your high-humidity climate affects their longevity.

cfitz

[Wayne]

I find it odd that my dentist has a DVD player in his reception room that has been playing the same disk for months, if not years. Maybe I should ask him, I probably paid for his Porsche