Hi.
This is a bit off-topic but an important subject given the growing
prevalence of digital, so I'll step in.
As a photograher specializing in archival access and preservation, I would
endorse a combination of Rob's approach (sensible burning, particulary with
file verification) with Steve's strategy (multiple hard drives), with one
added level of precaution.
The added level of precaution is to burn a copy of each CD on two different
brands of disc. CD formulations are subject to change without notice, and
even good brands can have bad batches. ("Gold Dye" discs appear to be the
best bet for longevity. This type of disc is getting hard to find. Mitsui
and Quantegy seem to be the prime remaining sources.)
Your main copies can be stored on multiple hard drives for quick access and
as the versions to be used for ongoing management and preservation. It is
more efficient to write from hard drives to new storage formats than to pull
up discs and do so. As well, error checking when copying on hard drives
seems to be a better bet than when writing to disc.
It is very important to back up carefully or use a RAID array, particularly
if you are storing edited images as they represent a significant time
investment.
Mainstream archival thinking seems to be tending to hard drive storage for
media such as sound recordings, video, and photographs.
For those on a limited budget, consider one set of properly burned gold dye
CDs (or DVDs- Quantegy makes gold dye ones for which they claim excellent
longevity.)- along with online storage of unedited images in JPEG 2000
format with 10:1 compression, edited images in TIFF format with LZW
compression, and backups of edited images in JPEG 2000 10:1.
In terms of CD longevity, the oldest CDs I use for image storage are Kodak
Photo CDs written from late 1993 to about 1999. Since then I have used
Kodak and Quantegy gold dye CDs. (Kodak gold dye CDs are no longer
available.) Other than one CD suffering from scratches, there have been no
failures among over 600 discs in my main offline storage system. On the
other hand, I have seen failures of off-brand CDs within a matter of months.
To keep somewhat on topic, I get quite a kick in my personal photography
from shooting with Spotmatics and S1a's, as well as varlous ancient
non-Pentax gear, then going digital for colour scanning and printing. I got
into photography when Spotmatics were hot stuff; the lenses still are in
their own way. Still like the darkroom for B&W.
At work? Well...Kodak DCS 14n. 13.5 megapixels is a lot better for copy
work than 6.
Cheers
John Poirier
----- Original Message -----
From: "Rob Studdert" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: April 22, 2004 8:41 PM
Subject: Re: CD-R lifetimes disputed
> On 22 Apr 2004 at 19:24, Joseph Tainter wrote:
>
> > Rob wrote:
> >
> > "I put my success down to sensible writing methods and storage
procedures."
> >
> > Rob, what are your sensible writing methods?
>
> Use a recognized brand name writer with good driver/software support and
> mainstream branded media. Use blank media free of dust or scratches (CDs
> supplied on spindles sometimes fail this criterion), ensure that the
system can
> deliver the data at faster than the CD writer speed, ensure good power to
the
> writer, hands off the computer until the media is burned and finalized,
always
> write and finalize an archive disc in one session, verify after write.
That's
> about it.
>
>
> Rob Studdert
> HURSTVILLE AUSTRALIA
> Tel +61-2-9554-4110
> UTC(GMT) +10 Hours
> [EMAIL PROTECTED]
> http://members.ozemail.com.au/~distudio/publications/
> Pentax user since 1986, PDMLer since 1998
>
