The pics at the bottom pretty much explain it. The first shows a regular Sony CD-R from a 50 pack bought at Walmart. I wanted to see how fragile CD-R's were in general since I knew factory stamped versions used a different method to embed the data within the plastic substrate that seemed more stable and durable. It didn't take very much effort to break the thin seal along the edge of the CD-R with the razor as shown. Once I got it started it was like pealing acrylic paint off a wall that didn't have a bonding primer underneath. The second pic shows how difficult it was to scrape through the top layer of a CD stamped at the factory. Big difference. Just FYI for you folks who've wondered about this. This may not be that big of an issue, but I was thinking of all those mp3 downloads of music everyone burns to CD so they don't have to buy the original stamped version. Of course most are burning to their iPod so no problems there. However, there may be concern for how long a CD-R will last with more important data like family photo's and what not. Solid state and flash based storage media may be the best alternative because who knows if the moving parts on an external hard drive will stand the test of time. Just thought I'ld share my findings here. Appreciate your thoughts on this and offer alternatives for more permanent and stable digital storage.
There are tons of websites documenting problems with long term reliability of CD and DVD media. The reflective layer can oxidize leaving the media unreadable. I'm sure plenty of other bad things can happen as well. The best thing is to stop thinking of permanent and stable digital storage and think instead of redundant copies and data migration. 20 years ago people may have had their data backed up on 100 floppy disks. That's fine but today it is more difficult to find a floppy disk reader. 10 years ago they should have copied all of those to a CD. 10 years from now CDs may die out so before then copy all of your CDs to whatever the current mainstream backup format is. Constant data migration is the only way to protect your data. Putting everything on "100% perfect 10,000 year gold archival media" doesn't matter if you can't find something to read that format. The most famous example of this is the electronic Domesday Book. The paper copy is still readable 1000 years later. The electronic copy was essentially unreadable just 15 years after it was made. http://www.guardian.co.uk/uk/2002/mar/03/research.elearning
I agree, no storage media is totally reliable and none will last forever. Not to consider future hardware and software backward compatibility, computer viruses and the risk of it being stolen. Backup the data, make backups of backups and consider backing up the hardware as well. Besides, all the CDs I burned back in the 90s became unreadable after 4-5 years. Luclkly they were scans of 35 mm slides and I kept the originals. I found memory cards and memory sticks that became corrupted after months.
Don, Oh definitely unreadable. Heck, breaking that thin seal on the outer rim of the CD wasn't even necessary because I could've nicked the surface on the inside of this seal and the pealing would've started from there. How often does a CD-R get nicked in normal usage? Makes you wonder. I was always more concerned with the scratches on the opposite plastic side. Now I'm concerned about both sides. Kelly, Redundant copies and data migration sounds like a good plan of action. It just seems like a lot of work and a lot of stuff to keep track of. Do you trust solid state media? What could go wrong with that? Could EMF and magnetic influence wipe these kinds of drives clean? I just got me an 8GB SanDisk Cruzer Micro Drive. Guess I'll pass over one of my speaker magnetics and find out. Thanks for the interesting link.
Love the line from Kelly's linked article. 'That means we have to find a way to emulate this data, in other words to turn into a form that can be used no matter what is the computer format of the future. That is the real goal of this project.'With a goal like that you might as well build a time machine and be done with it.
I came across some cd's I burned with some images 3 years ago. Half of which I could not read due to the age of the cd I guess. I keep hearing how long a cd is suppose to last but for me after 3 years the data may be gone forever. Seems to me that depending on what part of the cd the data was written to depended on whether or not I could retrieve it.
Derek, With both yours and Luca's experiences it's not sounding good for CD-R's. I've got a bunch of compilation music CD's I've burned as far back as 2004 and data CD's from 2003 on Sony brand, the same as the one pictured and they haven't given me any trouble so far. Might just get another 8GB SanDisk Micro Drive and transfer everything I have on CD's to these devices.
I have CD's I recorded in the mid-nineties that are still fine. I use quality discs. I never record at the highest speed. I always run the Verify Function after recording. I use proper storage methods. I wonder how a negative would look after abuse with a razor blade?
Well, I'm not Kelly but you should not trust ANY media 100%. Some people have washed flash cards in the washing machine and they still work but there's no guarantee. You can write to flash media thousands of times but it still has a limited number of writes and are susceptible to cosmic rays but my point is to keep multiple backups and migrate the data when that format starts to die out. Don't keep your backup on a Sony Memory Stick when that format is dead in 5 years and no one makes Memory Stick readers anymore. Also, don't just make backups. You have to test your backups. Just because your computer finished copying data to a hard drive, CD, flash card, or whatever doesn't mean that it copied the data correctly. Ideally you would have a checksum (like MD5) of every file and after the backup read the contents back and make sure it was correct. If your data is valuable then you should test the backup every 6 months or so to make sure it is still readable. Also keep backups in different locations in case of natural disaster (flood, tornado, fire, etc)
Marc & Tim, I know. I still play in the car music compilations I recorded in the '90s with the CD recorder. But on the other side everything that I recorded on CD with the computer did not stand the test of time. No matter the quality of the R-CDs I used at the time, some of which costed me a little fortune, and no matter the recording speed. I also checked the CDs after burning it, and it was fine. I was able to read them in the following months, and they were fine. Then, as years went by, I started having troubles and now every CD written with that PC is unreadable. This is one of the troubles of digital technology, either it works flawlessly or it does not work at all. This applies to data storage, telephone communications, digital radio or TV broadcast. It is not like analogue where a negative is still useful with a bit of discoloration and a telephone conversation is still understandable with some background noise. It is like digital has a red line, it works 100% even few inches before the red line and it is totally useless one inch after.
Digital is both a blessing and a curse. Anything worth archiving is worth redundant backups. For me, that means three copies (typically two on HD, one on DVD) of every valuable file, one of which resides off-site. This method is far from foolproof, but it's as much as I'm willing to do. Negatives and slides stored in a shoebox are more durable...
The archival CDs might be a better bet, even though they cost a little more. They're better quality than the cheap spindle packs and use gold as a non-tarnishing substrate. They won't replace the need for data conversion though - that's the side effect of digital at present. You'll probably need to check your backups every 5-10 years and move them to the current, stable, storage medium. If they're available, archival DVDs might be a better choice right now than CDs. I'm not sure of any tests that have been done regarding the long term stability of flash drives. Not sure I'd trust them to sit in a safe deposit box for a decade and still be readable. Hard drives are a better option, although you take the risk of no longer being able to physically connect them. Really though, this isn't that different than film's early days. Eventually some sort of long-term archival solution will be developed as the need becomes more apparent. Look at nitrocellulose film - highly flammable and has a tendency to destroy itself in storage, but it was in use for decades before an alternative was developed and widely used.
The important question is longevity of DVD+R. Materials and methods for assisting the longevity of CD-R are well documented.
"Negatives and slides stored in a shoebox are more durable..." No. You have a single point of failure. My negatives and slides are stored in several of those fire-proof Sentry safes. Any type of archival system requires the best methods and materials available.
Marc, I simply meant that of two things sitting on a shelf, one being a DVD full of images and another the proverbial shoebox, the DVD is much more likely to suffer unprovoked self-destruction.
Geez I must be losing it. WALT, I can't believe I called you Kelly. Sorry about that. I keep getting your name crossed with Kelly Flanagan who also posts in these forums. By the time I scroll to the bottom of these threads to post a meaningful, thought out response, my memory craps out on me. Names are the first to go. I'ld probably fare better if folks here posted an image of themselves with each response showing their name stamped on their forehead, but I don't even trust myself with that. To get back on topic, there's been some very good compelling responses on this issue and I appreciate the feedback. I started into digital back in '98 because I found it to be a very smart technology and a means to get out of the cumbersome analog ways of image processing. As a former prepress tech having to shuttle and organize endless amounts of drawers and vertical shelves of client's film based color seps, art pieces, mechanicals and paper work for permanent storage for several years, I embraced digital technology without question. Now ten years into it with everything I've researched and learned including WALT's article I'm not so sure. Luca's point and red line analogy about the absolute nature of digital pretty much covers it. It either works or it doesn't. At least with a box of negatives some of them may be bad and some may be good. At least you have something to work with. With digital you can either retrieve all the data or it's all gone. I'm probably over simplifying this and over concerned, but I feel like we've all crossed this wide river starting from the analog side to get to the full potential of digital and find we're now in the middle of it and can't go back. We either become constant stewards of our own and other's data or we lose it all. At least with digital we don't have to shuffle a huge flat file of materials year to year with all the dust and paper cuts it brings.
My view is similar to what Marc and Howard said. I use two HDs, two sets of DVDs, one offsite. Eventually one HD gets reused. Indexing is a key to usefulness. If CDs or DVDs won't play when you try them, it may be worth trying one or two other machines. I have some old CDs that only play in the machine they were written on, and a couple of DVDs that only play in a DVD writer, not a reader-only. Even older ones could be having problems with formats that aren't recognized by some machines. I think there were PC-to-Mac issues, too.... OTOH, aren't petroglyphs "a form that can be used no matter what..."?! Maybe the ancients were onto something. Hmm.
"With digital you can either retrieve all the data or it's all gone." Think about the people rescuing images from corrupted memory cards. It is not an all or nothing situation. "I have some old CDs that only play in the machine they were written on, and a couple of DVDs that only play in a DVD writer, not a reader-only." I would re-record with quality disc's and at a slower speed. Then check their readability on any other computers you have access to. You may find your recorder is going bad. You never want a recorded disc only readable on the recorder you used. "OTOH, aren't petroglyphs "a form that can be used no matter what..."?! Maybe the ancients were onto something. Hmm." Except for the petroglyphs that remain unreadable.
The complications involved with digital storage is a good reason for an additional kind of backup- prints.
