On Wed, April 30, 2008 15:56, w8imo@xxxxxxxx wrote: > On Wed, Apr 30, 2008 at 1:34 PM, David Dyer-Bennet <dd-b@xxxxxxxx> wrote: > >> >> On Mon, April 28, 2008 00:34, Trevor Cunningham wrote: >> > Here in lies a reason to prefer film over digital. Magnetic storage >> is >> > far more unstable than sleeves and notebooks. Burned storage has a >> > suprisingly limited shelf life, so we are learning. You can still >> play >> > your cd's from the early 1980's, but the commerically produced >> materials >> > are much higher quality than anything you can to make yourself. >> > Indeed, digital is less expensive...but, then again, it's cheaper >> >> Let's see; the first counter-case that comes to mind is the photographer >> who died in the WTC attack. The film in his film camera was >> unrecoverable, but all the images on the flash memory card were >> recovered. > > > Fortunately this is not a common occurrence. It is also not an example > of > long term storage. Fortunate indeed. And it's definitely not a long-term question, no. But it *is* a question of the relative stability of different storage media. Some digital media are *better* than analog media at surviving harsh conditions. >> There were also a collection of important negatives of the Kennedy >> family >> in a safe-deposit vault under the building; you may have seen the book, >> made from prints and contact sheets sitting around that photographer's >> studio. If the data had been digital, there could have been more than >> one >> copy, and it likely would have survived. > > > How do we know? Because the total area that was devastated in that catastrophe was relatively small compared to the area within which he would have been choosing a location for a backup copy. The same is true of every single other catastrophe on which we have information. So if you keep *two* copies in different locations, with even minimal thought to avoiding their being involved in the same catastrophe, the odds are very good that at least one of them will survive. And I only claimed "likely", I did not make any claim of certainty. My off-site backups are in my mother's house, 35 miles away from home. House fires are moderately common, small floods (and my office is in the basement at home) also common, but none of those would involve my mother's house at the same time. Even a *big* fire that destroyed my whole neighborhood wouldn't get my mother's house. And the Minnesota river valley is between them so they won't be in the same flood, either. It would take quite an unusual disaster -- probably something bigger than has happened since Krakatoa -- to get both sets of my digital photos. It's more likely that a disaster would get one set plus me, since I spend considerable time in or close to home. The Corbis digital archives would be even harder to completely destroy -- they have copies more widely separated, and each copy is better protected. They, of course, are spending lots of money protecting their archives, whereas I'm spending relatively little, just the cost of good blank disks and the time to burn them (I deliver them on visits I'd make anyway, so that doesn't count as a cost of my backup program). >> Digital archives work wonderfully *when competently managed*. They are >> *horrible* for long-term benign neglect. The ability to store multiple >> copies in separate locations gives you the ability to protect against >> problems that are intractable in analog (where copies are not only >> expensive but *inferior*). > > > All archives, digital, film, paper, etc need 'competent management' to > remain viable for very long times. To remain viable reliably, yes. But we have written works that survived only because a copy sat in a barn for 400 years at one point, and was eventually discovered. >> Analog media degrades constantly over time, but sometimes fairly slowly. >> The right analog media do pretty well with long-term benign neglect. >> >> So what I see here is that they have different characteristics, and so >> one >> is better for some things, the other is better for others. > > > True. But as I saw a few years ago, someone was having difficulty getting > data off of a 5.25" diskette but was able to print a sixty year old > negative. > > Some time ago I found a box of Kodachromes date stamped by Kodak as 1976 > that I had lost. Many were dirty but the images, to the best of my > abilities are like they were in '76. I haven't louped any of them but > when > projected after cleaning they still look good. Yep; but those are both examples of digital media not working at all well in a scheme of neglect. While for best long-term results all media need careful attention, some analog media do a lot better under benign neglect than any digital medium so far developed. So those results aren't surprising. And I have boxes and slide sheets of ektachromes from the early 70s that show considerable fading. > > This is an interesting thread similar to Canon vs Nikon and Ford vs Chevy. > Just as long as it's not like Mac vs. Windows ;-) -- David Dyer-Bennet, dd-b@xxxxxxxx; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info
