How long do they last?

[justleesa]

The other day my SO was listening to the Kim Komando show and he heard something about the fact that the data we burn onto CDs (our pictures) only lasts about 2 years (or less) depending on how they are handled....he went back and looked up the show and came up with this:

http://www.komando.com/kolumns_show.asp?showID=5747

Should I make a copy of a copy of a copy (already am making 2 for safe keeping) to ensure the life of my photos?

 

[nwdiver2]

Good quality CDs will last a long time I have music CDs from the early 80s that are still fine. Cheap CDs may not last as long. Abused cheap CDs may last only several months. Use high quality CDs for long term storage. We ran into the same question in the medical records field and found to our surprise, CDs are not all the same I use the good $0.55 (wholesale) ones not the cheap $0.28 ones for patient studies and records.

The Kodak archive CDs at $2.50?? each (retail) are said to be the best available. I moved to high quality DVDs to get 4.5gig (or so) per at $9.50 each for long term storage. This was cheaper than the 640 meg CDs.

 

[ScubaTexan]

That's a new one on me, Lisa. I was always under the impression the burning was permanent, unless you accidently erased it somehow.

 

[justleesa]

I know that the music cd's are pressed and last...just the ones you burn are not 100%...I guess I'll let you know in a couple a years...I think I use the cheapos...lol

 

[lukeROB]

I know that the music cd's are pressed and last...just the ones you burn are not 100%...I guess I'll let you know in a couple a years...I think I use the cheapos...lol

You are right. Music CD's are stamped from master molds. The pits are physically pressed in there (no need for details). However burnt CD use different laying which reacts to light or heat to create the pits. Cheaper CDs use cheaper layers and less of protective layers, etc, etc. They will probably not last very long - maybe a couple of years. Music CD should last a good long while - 100 years maybe if treated well.

Often the photosensitive layers used in cheap CD-R/CD-RW deteriorate without any use. Unfortunatly this is something that you have to live with. Buy good quailty CD-R's is my only tip. Maybe make a double backup and check them in a couple of years and maybe reburn them (there will probably be better modes of storage by then )

Anyway enough babble. BTW I think DVD-R would use similar principles (just smaller tracks and multiple recording layers). Trusting lots of data on a single 4gb disk could be risky in my opinion.

 

[justleesa]

You are right. Music CD's are stamped from master molds. The pits are physically pressed in there (no need for details). However burnt CD use different laying which reacts to light or heat to create the pits. Cheaper CDs use cheaper layers and less of protective layers, etc, etc. They will probably not last very long - maybe a couple of years. Music CD should last a good long while - 100 years maybe if treated well.

Often the photosensitive layers used in cheap CD-R/CD-RW deteriorate without any use. Unfortunatly this is something that you have to live with. Buy good quailty CD-R's is my only tip. Maybe make a double backup and check them in a couple of years and maybe reburn them (there will probably be better modes of storage by then )

Anyway enough babble. BTW I think DVD-R would use similar principles (just smaller tracks and multiple recording layers). Trusting lots of data on a single 4gb disk could be risky in my opinion.

right now I am upgrading my photo system and paying my tuition....so a dvd burner is on tha back burner for now ...now what CD's would you suggest?

 

[ReyeR]

The music and software CDs you buy from the stores are made by injection moulding the 'bumps' and 'pits' (the '1s' and '0s' ) into the polycarbonate and covering with a reflective layer of aluminium. The CD-Rs we burn uses an extra layer of dye which is sensitive to the heat of the burning laser. This heat changes the transparency of the dye layer (making it opaque) forming the 'bumps' found in the factory-pressed CDs. It turns out this dye layer is sensitve to light too.

It's easy to see why the factory-pressed CDs will be more robust compared to the dye-based CD-Rs. So keep these CD-Rs away from direct sunlight and heat. I burn 2 copies and store them in 2 separate locations (in case of fire etc) in a cool, dark and dry place. And do yourself a favour - avoid printing those snazzy round sticky CD labels and sticking them on your precious CD-Rs. I've had difficulty reading these CD-Rs because of the labels. Apart from that I've got music and data CDs that were burnt about 8 or 9 years ago and still working fine.

 

[lukeROB]

The music and software CDs you buy from the stores are made by injection moulding the 'bumps' and 'pits' (the '1s' and '0s' ) into the polycarbonate and covering with a reflective layer of aluminium. The CD-Rs we burn uses an extra layer of dye which is sensitive to the heat of the burning laser. This heat changes the transparency of the dye layer (making it opaque) forming the 'bumps' found in the factory-pressed CDs. It turns out this dye layer is sensitve to light too.

It's easy to see why the factory-pressed CDs will be more robust compared to the dye-based CD-Rs. So keep these CD-Rs away from direct sunlight and heat. I burn 2 copies and store them in 2 separate locations (in case of fire etc) in a cool, dark and dry place. And do yourself a favour - avoid printing those snazzy round sticky CD labels and sticking them on your precious CD-Rs. I've had difficulty reading these CD-Rs because of the labels. Apart from that I've got music and data CDs that were burnt about 8 or 9 years ago and still working fine.

All correct.
My only other comment would be that I think I read somewhere that CD-R with a true gold layer are superior CD-R's. Maybe you can shed some light on this ReyeR.

 

[ReyeR]

All correct.
My only other comment would be that I think I read somewhere that CD-R with a true gold layer are superior CD-R's. Maybe you can shed some light on this ReyeR.

I haven't heard of that one but logically I would imagine that the stability of the dye layer would be the key to the life of the data....

 

[fdog]

The source for this came originally from a London-based newspaper. I read about this from Network Computing magazine, and the article mentioned that the tests have been replicated elsewhere.

Essentially, they took a bunch of archived dye-based CD-Rs out of dark, temperature controlled storage and tested them for data dropouts. There were significant such dropouts on CD-Rs older than roughly 2 years. There were no correlations between "premium" and "cheap" and resistance to data loss, nor the reflective substrate (gold vs aluminum). The speculation is early dye fade.

Interestingly, CD-RWs displayed no such data loss as related to age. This is probabally because they do not use dyes.

All the best, James