Life expectancy for analog negative
We often hear the claims of archival longevity of digital images and data mediums. I am curious if there is any difinitive answer as to the longevity of a optimally processed and stored analog negative on modern polyester substrate. I would assume under proper storage it could be indefinetly. Any facts that support an actual length of time?
"Fundamentally I think we need to rediscover a non-ironic world"
In one of those frozen vaults, it will last a looooooooooong time. Longer than needed. Longer than us and all those that follow. Remember, it's just a negative. At the rate photography sells, it seems to me that negatives are worthless and prints only slightly less so.
Bad mood this morning.
Unless people throw them away! I was watching a home organization show last night and one of the phrases used by the organizer was, "The negative isn't important, there are lots of places to get the print scanned." I wanted to scream at the tv.
here's a place to start. go to the IPI and I'm not sure where it is on their website now, but download the free report "IPI Guide to Acetate based Film Storage" for starters. This mainly about the mechanisms of vinegar syndrome and measures to be taken as far as archival management, but it also gets into polyester based support as well. Also, download the free program, the IPI "Preservation Calculator". This handy little thing extrapolates temp & humidity factors against accelerated estimates for film deterioration (again mainly acetate based, but it's handy for tracking humidity problems in association with mold and other factors).
You can also but these in a guide book with a wheel for the calculator, and IPI has several other publications such as color slide longevity that deal with this as well. Some of these are for sale, some are free online. One such thing is the Climate Notebook study they run, with the interactive Stored Alive.
Finally--the IPI has a seminar they give every year about managing photo collections. It's a week long and they address all sorts of issues and current research and methodology in terms of archiving. It's geared towards people working in the field, not photographers per-se, but I went to one of these at the smithsonian, and it was well worth the money.
fwiw--the line of thinking in the place I work for has always been that the negatives (and microfilm) are the record for the most part (exception would be prints collected as artifacts, but that's another topic). The negatives trump all else. The prints made from the negatives might someday deteriorate, but you'd still have the master file and any duplicates as well. The prints are accessing these files, not the end all and be all...it's all about information--and that's a stumbling block for people who view prints as being the final product. Not that there's anything wrong with that, but negatives are important for the future. Nobody can really say what that will hold, but if you work in an archive or a museum, that's part of the job. To think otherwise it's just stupid--my opinions only of course.
Longer than you will care is the succinct answer. The problem is not how long they will last, but will your heirs want to keep them.
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I do not know how long they will last but including selenium toning in your processing as well as Sistan will be helpful. Or course freezing will greatly prolong them.
Claire (Ms Anne Thrope is in the darkroom)
They (Nat Geo) was able to print found glass plates from William Perry's expedition back in the 1980's. Now that was cool!
Wow, 25 years!!!
I think you meant 1880.....
Yah, my Engrish isn't that good. 1880 was a little too early.
Originally Posted by KenM
Here's a rehash (where's my tech writer when I need him!)
They (Nat Geo) was able to print found glass plates (found during 1980's) from William Perry's expedition in 1909. Now that was cool!
Lots of collodion glass plate negatives are still good from the 1850s, when they were invented, and a goodly number of Daguerreotypes from the 1840s as well. Some of Fox Talbot's earliest kallitype paper negatives have survived, from the 1830s (once Herschel showed him how to fix them to remove the unreacted silver chloride).
So we can reasonably presume that a silver image can last, at a minimum, something like 200 years with so-so storage and no particular effort at conservation.
There is reason to believe that sulfide toned silver images will last more than 500 years (given that they can be demonstrated to be several times as durable against environmental stresses as plain silver images).
A polyester film base, protected from excessive heat and UV exposure, is likely to last a similar time -- 500 years or longer -- and the gelatin that carries the silver in modern films is similar to the connective material in leather, of which we have examples, still intact, dating back as much at 10,000 years. Likewise, cellulose paper can last at least 5000 years, as long as it's kept dry enough not to sustain mold growth. Acetate does a bit less well, and nitrate a lot less well, but even those can last a very long time if they're stored in conditions that don't encourage their inherent tendency to deteriorate.
So, it's reasonable to expect that, simply stored in ordinary containers in living and storage spaces suited to other items we live with every day, silver image, sulfide or selenium toned negatives and prints can last several centuries without further human intervention (they might not, depending on a bunch of factors we don't control, like natural distasters, as well as some we do, like initial processing conditions, but the materials are at least capable of this longevity). Add to that the fact that the most cursory examination will show (to the naked eye) that they carry a picture, and these materials are at least a little less likely to wind up in a landfill than some things...
Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.