There is also the "cost" of doing the storage job. Moving files around
or writing them to DVD takes time - probably more than handling the negs
in my experience. Then it is a question of how paranoid you are. Should
you trust the DVD media (which does not really have a proven track
record)? Do you want redundancy, and how much? At work, we use tape
media with quite a bit of overlap, and trust me, this will be a lot more
expensive than film. But it's a lot safer, too (I mean, I'd probably
trust one negative more than one DVD or tape, but not more than 3 or 4
copies on different tapes stored at different locations....) Still, it's
the time taken to handle the data that's the main issue, not the media
cost. And yes, this increases a lot when you keep data on-line instead
of archiving the data directly.
Interesting perspective, given my fairly lengthy experience with tape and
optical media I'd say that optical media would be an order of magnitude more
reliable than tape media.
Tapes are the most commonly used media for backups on large computer
systems. They have a longer expected shelf lifetime than anything else.
Firstly I still haven't heard instances of optical
discs (DVD or CD) that have been stored appropriately failing.
I haven't seen it myself, either. But some of the people who use CDs for
professional archival will renew them (as in copying the data to new
medium) every 5 years. Apparently, they are most concerned about media
separation, i.e. that the disc literally falls apart.
What I have seen, are CDs that just can't be read after they were
written (not a big issue except you loose a CD), ones that seem OK, but
have data inconsistency at some point, and also (this is the really
dangerous one) ones that seem all right, but will only work with certain
readers. The situation was probably a lot worse than it is today a few
years ago, though, when CD writers were young and inexperienced, to put
it that way...
I have however
seen worn, tangled tapes and shedding and dirty heads and incompatibilities due
to head misalignment and firmware/software incompatibilities.
I think you are talking about tapes that are worn out due to reuse over
a long time (or maybe something different from professional-grade backup
solutions.) That's a different issue entirely. Also, one advantage of
tape is that even if the tape gets torn, you should still be able to
retrieve most of the data. While a CD/DVD (allegedly) is more likely to
disintegrate completely, meaning that all the data will be lost.
Give me DVD over
tape any day.
Time, when was the last time you cut and sleeved ten rolls 36 exposure film
(roughly equivalent to the number of *ist D RAW files I can fit on a DVD)? I
can assure you it would take longer than writing and verifying a main and back-
up DVD.
No, I don't cut my film...
[ ... ]
Another thing is that when people talk about how much cheaper digital
is, they seem to be comparing with the price of developing *and
printing* from film, which does not seem fair...
I don't, the cost of (good) film and (professional) developing is significant
enough and since prints are cheaper from a digital source so I'm sure it's not
fair to include them.
Possibly cheaper, but not costing nothing (far from it). (And you do get
cheap "package" options for film, where the prints definitely don't cost
more than the ones from digital.)
We've discussed this before, of course...
I think digital will *really* make a difference as and when the actual
media used in the camera becomes so low-cost and reliable that you won't
have to copy the data at all. (But I've probably mentioned that earlier,
too.)
I think it's insignificant enough now that the vast majority of RAW shooters
here consider it a non-issue.
Do they?
- Toralf
