Re: Digital

Tom Phillips <[EMAIL PROTECTED]> writes:

> David Dyer-Bennet wrote:
> > Modern film stocks also decay, and especially color dye images decay.
> 
> Not if stored properly. 

Have *you* read Henry Wilhelm's book (_The Permanence and Care of
Color Photographs: Traditional and Digital Color Prints, Color
Negatives, Slides, and Motion Pictures_,
<http://www.wilhelm-research.com/book.html>)?  Do you have other
experience in the field?  Or where are you getting your crazy ideas.

As I've said, I have color slides *that I took myself* that are
seriously faded.  I know how the've been stored -- in archival
sleeves, or archival boxes, in air-conditioned residential areas, for
their entire life. 

Yes, you can reduce the rate of loss by frozen storage, but that's not
as easy as it sounds (I've read about the issues).  But if you're
prepared to provide that level of care, you can probably handle a
digital archive as well, and if you do there's *no* quality loss.

And, the big point -- you can *never* reduce the loss rate to zero.

> Digital media decays regardless.

Also true.

> > Nice phrasing, but I'm afraid "real data" is more permanent than "just
> > an image" in my experience.
> 
> Experience has nothing to do with it. Data is just 1's and 0's, not a
> "real" image. That's a fact. The "data" is no more permanant than the
> machines and media it's stored on, which have exceptionally limited
> lifespans. That's also a fact. By contrast, we have photographs that
> have already outlasted anything stored on CD by at least 170 years.

"Real" images are something that happens in my head, and I don't
really care how the data was stored.

> > You over-estimate the permanence of film by a *lot*. 
> 
> No, I don't. The estimate of the permanance of film is from the
> Image Permanance Institute. Get their reports and read. Thousands of
> years are possible. IPI is a *nonprofit* research organization
> staffed by independent scientists. Henry Wilhelm is a paid industry
> consultant and mouthpiece.

Henry Wilhelm is the guy who *invented* this field of expertise, and
widely recognized as the premiere researcher, whereas I've never
heard of this IPI group.  Okay, googling I see they're a group at RIT,
and I *have* heard of a group doing work in this area at RIT; but they
don't have the stature Wilhelm does in the field -- and they don't
disagree with him much that I've noticed, either.

> > I have severely
> > faded slides and negatives taken during my lifetime, including some
> > taken by me.  The ones taken by me I pretty well know the storage
> > conditions of, and they're close to as good as it gets (short of
> > controlled-humidity refrigerated storage).
> 
> Store your hard drive in a refrigerator and the magnetic data still
> fails in a given number of years. Film, b&w or color, lasts indefinitely
> in cold storage. That's not my "Phrasing," but the opinion of scientists
> and film preservationists everywhere.

No it isn't.  Nobody I've talked to agrees with that analysis.  At
best you can *reduce* rate of loss. 

> > While many of your points on digital archiving are accurate, you
> > overplay your hand.  In particular, a single-bit error doesn't ruin an
> > entire image inherently and necessarily.  Even in jpeg format, it at
> > most damages the parts of the image after it; and there are other ways
> > to archive images.
> 
> Oh come on. If you have data corruption or media failure, it's never
> "single bit," It's usually unrecoverable. Happens all the time. I've
> never gotten an error message that says "this file is only partly
> corrupted." A file is either usable and readable or it's not. And it
> doesn't take a lot to make it unreadable. Image format is irrelevant.
> Plus I'm talking about raw data, not a compressed format like JPEG which
> isn't even desireable for digital images (not professionally.) I would
> never store a digital image as a compressed file.

In a TIFF file, one bit of damage makes a change to one pixel.  

I've seen *lots* of jpegs (not mine) that clearly have a single bit
error, where everything after a certain point is off-color.

I've had mostly-recoverable media failures dozens of times in my life,
and with CD and other high-density optical storage it's a way of
life.  There's a lot of error-correction going on in the drive.  I've
got a utility that will monitor that, so you can monitor the gradual
decay of the media, and copy before it's too late.

> > > If you want to believe the fallacy that digital is permanant, or is more
> > > permanant than film, it's your choice. But it's a lie.
> > 
> > Well, actually it's more complicated than that.
> 
> It's a marketing lie oft repeated that digital is "permanant" and film
> "isn't. 
> 
> > B&W film lasts better than anything in *untended* storage.
> > 
> > Color film does okay in careful archiving for modest periods, but
> > requires refrigeration (and then humidity control) for really long
> > life -- which means stuff just lying around, even in a residential
> > area, *doesn't* survive all that long.
> 
> I said "proper" storage." That means cold dark storage. I also mentioned
> IPI. The details are available from them if one isn't too lazy to do
> one's own research. Color dye films, BTW, such as kodachrome or
> ektachrome last as long as black and white in proper storage.
> "Refrigeration" is a relative term. Below 60F is all that's required for
> general longevity. There are color photographs 150 years old that are in
> mint condition and they've not been refrigerated for most of that time.
> Essentially, cool dark conditions with air circulation and not too much
> humidity is conducive to preservation. You don't necessarily need a
> climate controlled vault. You're under-estimating.

You need a climate-controlled vault to achieve low humidity and under
60 degrees anywhere *I've* lived, and I've never even lived in the
South. 

And if you have to go to the trouble of climate-controlled storage,
you're not really much better off than the trouble you have to take
for digital.  It doesn't address finding old photos in the attic at
all! 

> > Digital does fairly poorly if just left lying around -- magnetic media
> > maybe 5 to 20 years.  
> 
> Digital or magnetic media does poorly regardless. 

No, CD's expecially are really wonderfully reliable for short periods
-- and will withstdand spills and things that would really ruin film.

> > CDs longer.  However, if managed well, the
> > information has the potential to last any length of time you want,
> > something which is *not* true of film images.
> 
> You don't know what you're talking about, sorry. CD-Rs don't last very
> long. The technology that reads them lasts even less long. Plus digital
> information is intangible. Meaning you can't leave it unmaintained an
> attic and hope it will be there 100 or 200 years from now, as has been
> the case with actual photographs, including color images like
> Autochromes. Digital *has* to be stored and maintained (redundantly),
> electronically retrieved, and read. *IF* that information somehow
> survives data corruption, say, 100 years storage in your attic or
> basement, the likelihood is you won't be able to access it due to
> changes in technology.

By your own testimony, you can't leave color images in the attic
untended either -- you said under 60 degrees and low humidity.  And
I've already agreed that digital archives require attention, that
digital media don't work well in untended storage. 

> > The issue of having to copy "thousands of photos" is semi-bogus -- the
> > new medium is nearly always larger than the old one, so you can just
> > bulk-copy everything.  You don't actually have to deal with each
> > single image separately.
> 
> Raw data files can be quite large. I'm not talking about low res
> prosumer JPEGS.

Neither am I.  My scanned images are 25 megabytes and up, digital
camera originals get as big as 36 megabytes.  

> > In fact, hard drives are growing so fast that what actually makes
> > sense, for individual photographers, is to keep everything online,
> > with copious and frequent backups.  
> 
> Anyone who stores their images in an online archive (again still
> magnetic media/hard drive), is a risk taker. Such images are not "safe,"
> plus you're trusting someone (or something) else to ensure the viability
> of your digital images and *completely* dependent on them and the
> economy of that business. And if you have to copiously and frequently
> back it up (which you do since hard drives frequently fail) what's the
> point? Better to photograph using a permanant media like film and then
> scan. Then you have an "hard" copy original that's permanant and can
> always make a digital copy.

Huh?  How am I trusting somebody else?  I'm talking about *my*
frigging hard drive sitting in *my* computer on *my* desk. 

I'm converting my thirty year backlog of film to digital to get better
prints and better permanence.  The original negatives/slides are
fragile and delicate and unique, and getting them stored safely in
replicable digital form is a *big* load off my mind.

> > One of the *big* benefits of digital archives is that they can be
> > replicated and stored in multiple ways in multiple locations.  This
> > *greatly* increases the chances of images surviving various sorts of
> > problems (fire, flood, tornado, earthquake, hurricane, civil unrest).
> > Consider the Kennedy negatives that were lost because they were stored
> > safely in a bank vault -- under the World Trade Center (the
> > photographer was Jacques Lowe I believe).
> 
> Guess there's no accounting for what terrorists will do. I seriously
> doubt they'll fly a plane into my basement filing cabinets, though :)
> Let's just consider your multiple location idea: Still just computer
> storage, still magnetic media, still dependent on the power grid and
> back up redundancy. I suppose you might consider that redundancy enough
> of a safeguard. But of course if the terrorists strike again, like I say
> they're not going to be interested in my house, but in some major target
> like the power grid and computer networks :)

Your basement will flood first.

And my hard drive isn't dependent on the power grid; yanking power
won't damage it (and besides it's on a UPS, so it'll get shut down
gracefully). 

> > In 750 years, there will be essentially *no* photographs from this era
> > known because their original physical medium has survived, and
> > millions of photographs from this era (including many originating on
> > film) that are known because they survived in digital archives.
> 
> nonsense.

Wait and see.
-- 
David Dyer-Bennet, <[EMAIL PROTECTED]>, <www.dd-b.net/dd-b/>
RKBA: <noguns-nomoney.com> <www.dd-b.net/carry/>
Photos: <dd-b.lighthunters.net>  Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <dragaera.info/>