On Thu, June 25, 2009 11:11, steve harris wrote: > Do the members on this list think that the half-live of photo images has > significantly shortened, because of the shift to digital? What about > different categories of images (professional vs consumer)? There are all sorts of ways to slice and dice what information we have. A lot more images are permanently deleted early on, I think. If that sort of infant mortality is included, that lowers the half-life. On the other hand, more images are shot (at least that's the report of everybody who has used both film and digital), so even if the life of average images is short, the life of a photo from the session may be higher. Ordinary consumer images were mostly on ordinary chromogenic negative film, and printed similarly. As digital came on, I started finding long-life papers at some of those places (Fuji Crystal Archive, for example), but most of them during most of the film era used ordinary short-life paper. Good quality CD and DVD blanks probably last longer than ordinary chromogenic materials, and possibly longer than Crystal Archive, from what I've seen published. Archival-grade blanks should definitely last longer than any chromogenic materials. Furthermore, the ability to make multiple copies makes it possible to improve the chances of a photo's surviving by having multiple copies in geographically dispersed locations. I don't know how widely used this capability is. I know a number of people who have participated in scanning *old* family photos, and a part of that process has always been making DVDs (or CDs previously) and sharing them around among the family members; but I don't know how often that's done with digital original pictures (I've done it in cases where there was interest, but we already know I'm not normal, eh?) And of course some people are just keeping the photos on their hard drives, not backed up on anything; those photos have a short half-life. Lots of people put their photos on Flickr and other services. Those services are much more secure than holding them on their own hard drives *in the short run*. And perhaps the medium run. I'm not nearly as clear about the long run; how long will Grandpa's Flickr account stay accessible after he dies? Will people remember to keep paying it until they rescue the photos they care about? On the other hand, those services make it possible for family and friends to grab copies of the ones they like easily, thus again creating multiple dispersed copies and greatly increasing the half-lives. One thing you definitely lose with Flickr is stumbling on the albums in the box of old books decades later. DVDs are less clear; they should last okay for decades, most of them; but possibly not as long as silver gelatine B&W prints. Probably longer than chromogenic color prints and negatives. They're susceptible to somewhat different problems. Furthermore, when going through a cache of old stuff, it's much easier to glance at photos in a box or an album and see that they're interesting than it is to glance at a DVD and reach that conclusion. And if you hit the box of Grandpa's 200 archive DVDs, it's enough to daunt even the most dedicated family historian I would think. (I'm not that concerned about the drives being unavailable for a while now; when I look at how long the LP lasted, and note that people can *still* buy equipment to transcribe 78s which become obsolete around the time I was born, and that DVD drives read CDs (and even write them), I feel rather reassured. Timescales of 500 years are another matter; it's much harder to even think sanely about that kind of interval. But chromogenic materials in casual storage are toast over that timespan too. I have an image in my head of people finding an old DVD in 500 years, and just putting it in their "atomic scanner" and then applying the DVD format specification data from the net archives to the output of the scan, and getting most of the data back.) Generally speaking, digital media does MUCH better than analog media in "curated storage" -- where people are actively taking care of it with some intelligence. And over the long term it does EXTREMELY poorly under "benign neglect". I describe digital archives as being rather 'brittle'. Still, copying and dispersal helps a lot. > Should a criteria of technology be the lengthening, rather than the > shortening of photo image half-life? Generally speaking, yes. Making prints and archive media more permanent is good, encouraging people to think about it is good, but a scheme to convince people to shoot a lot fewer pictures on the grounds that they would value them more and care for them better is IMHO not good, even though it might well increase the half-life. (I have formed the impression, from a couple of recent posts plus some vague memories, that you're a bit of an anti-digital zealot, focusing on archival preservation arguments. I apologize if this is inaccurate; I'm sure it's incomplete at best. In preservation arguments, I find I mostly speak on the pro-digital side because the other side is generally being well-represented already, and many of the benefits of digital for archiving are being overlooked. And I'm always pleased to learn more actual information, whichever side it supports. I'm strongly interested in historic preservation, both of photos WE consider important, and of ordinary photos of everyday life for future historians. I practiced "archival processing" with my B&W materials from very early in my hobby activities, because I liked the idea of photos traveling into the future.) -- 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
