CDR's--burned CD's--are susceptible to a type of rot or deterioration in the media (not so different from the deterioration of nitrate film base VERY volatile or the now emerging issues with acetate film base that's gives it up to become vinegar). Pressed CD's (commercial programs and music) are less vulnerable.
Another point--the guy doing wet plate or platinum or ambrotype is basically making his own media, how many of us are capable of making our own CD blanks or CD writers?
Not that I'd want to but I could make a Talbot type salted negative and a pinhole camera from items around the house. (OK, I cheated--I have 75 pounds of sodium thiosulfate in the basement--but you can buy it from pool supply stores--ditto sodium sulfite. Sodium carbonate from the grocer, ascorbate from the drug store, etc.
darkroommike
---------- ----- Original Message ----- From: "Bob Talbot" <BobTalbot@st-abbs.fsnet.co.uk> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@listserver.isc.rit.edu> Sent: Tuesday, November 11, 2003 1:20 AM Subject: Re: Digital and film, was didgital is a musing.....
> > I lost several CD's of digital photographs in a matter of a couple > > months and they were just sitting quietly in their jewel cases on > the > > shelf. They were irrecoverable. > > Sidney > > > I write two copies of EVERY CD I make for backup/archival purposes and > I check that at least one file from each is readable. Ideally i'd > verify every single file but that would take for ever. > > CDs are not immune from deterioration. The bigest "threat" to digital > files is that they just get forgotten. Unlike neg's there is no > physical reminder you might be conveying something important to the > trash can. Archiving digital data (work context) is an active and > ongoing process. It does not just happen, the media needs to be > refreshed every couple of years. Old slides might fade over 20 > years, but at least there is something there. Digital is binary: > it's there or it's not - instantly. > > > Jeff has it nailed: multiple cpies at multiple sites ... it's that > much effort. >
Mike,
RE the pool supply hypo - what's your formula for film and paper fixer using that stuff?
Where do you get your info RE deterioration of home-burned CD's? Making a back-up copy wouldn't do much good if the things "rot" as you say.
Why not freeze them?
AZ
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