4 ms·

Hard to evaluate if that is wise. Microfilm is a much easier to read media than any digital form that achieves the same density.

kragen 5y ago
It seems like a pure improvement if they're still preserving the microfilms. Any digital form can be copied indefinitely without degradation; microfilm can't. And a library of digital copies is enormously cheaper than a library of microfilm. A reasonable source for film costs might be http://www.matthewwagenknecht.com/the-actual-costs-of-film/ http://www.matthewwagenknecht.com/the-actual-costs-of-film/ which says 16mm (color) movie film is US$197 for a 400-foot roll. That would be enough for 12000-20000 A4-sized pages at typical microfilm linear reduction ratios of 20-25, so about 1¢-1.5¢ per page. Black-and-white or diazo film might be a little cheaper, but probably not more than a factor of 2. Microfilm stock might actually be more expensive (finer grain, lower-volume product?)—does anybody know? By contrast, a page of ASCII text is about 4KB, or 1.2KB if gzipped (which, yes, could create risks to accessibility). A new 2TB disk costs US$45. So making a copy of the transcriptions these volunteers created costs 0.000003¢ per page. For the price of a single 400-foot roll of 16mm film, capable of holding tens of thousands of pages, you can buy five 2TB disks, which can hold 1.7 billion pages each, and put a copy of your corpus to be preserved on each one. If we're looking at preserving scans of the pages, well, I have a PDF scan of Volume 3 of Dr. Dobb's Journal here from the Internet Archive. The pages are scanned at 2550×3300 (300 dpi) in grayscale, which is considerably better than any quality I've ever seen on library microfilm, and the 484 pages weigh in at 232MB, 500 kB per page. So a US$45 2TB disk can only hold 4 million pages scanned at this sort of archival quality, a cost of 0.001¢ per page. That's still literally a thousand times cheaper than microfilm. Hard disks have some real problems with longevity: paper will last 1000 years if well-treated, microfilm will typically last a century (though it tends to get scratched if used, and nearly all microfilm is acetate rather than PET, so many microfilms succumb to vinegar syndrome in only a couple of decades), but disks tend to develop problem with stiction in only 10-20 years, and they wear out and fail catastrophically sooner than that if they're in use. Right now the strategy is to copy the digital data to new media every few years, and try to use archival file formats. So we need to do much, much better. But the costs are now so low that a hobbyist can put ten thousand scanned books in their pocket; in an afternoon they can make a digitally-perfect, checksummed archival copy of a thousand books, using a couple of dollars of disk space and BitTorrent. In the microfilm age that would have been impossible for anyone but a librarian, and a nontrivial cost for the library. You sound like you might be interested in https://dercuano.github.io/topics/archival.html https://dercuano.github.io/topics/archival.html, which discusses ways to improve archival, especially digital archival. I think there are some straightforward approaches to

kragen 5y ago

It seems like a pure improvement if they're still preserving the microfilms. Any digital form can be copied indefinitely without degradation; microfilm can't. And a library of digital copies is enormously cheaper than a library of microfilm. A reasonable source for film costs might be http://www.matthewwagenknecht.com/the-actual-costs-of-film/ http://www.matthewwagenknecht.com/the-actual-costs-of-film/ which says 16mm (color) movie film is US$197 for a 400-foot roll. That would be enough for 12000-20000 A4-sized pages at typical microfilm linear reduction ratios of 20-25, so about 1¢-1.5¢ per page. Black-and-white or diazo film might be a little cheaper, but probably not more than a factor of 2. Microfilm stock might actually be more expensive (finer grain, lower-volume product?)—does anybody know? By contrast, a page of ASCII text is about 4KB, or 1.2KB if gzipped (which, yes, could create risks to accessibility). A new 2TB disk costs US$45. So making a copy of the transcriptions these volunteers created costs 0.000003¢ per page. For the price of a single 400-foot roll of 16mm film, capable of holding tens of thousands of pages, you can buy five 2TB disks, which can hold 1.7 billion pages each, and put a copy of your corpus to be preserved on each one. If we're looking at preserving scans of the pages, well, I have a PDF scan of Volume 3 of Dr. Dobb's Journal here from the Internet Archive. The pages are scanned at 2550×3300 (300 dpi) in grayscale, which is considerably better than any quality I've ever seen on library microfilm, and the 484 pages weigh in at 232MB, 500 kB per page. So a US$45 2TB disk can only hold 4 million pages scanned at this sort of archival quality, a cost of 0.001¢ per page. That's still literally a thousand times cheaper than microfilm. Hard disks have some real problems with longevity: paper will last 1000 years if well-treated, microfilm will typically last a century (though it tends to get scratched if used, and nearly all microfilm is acetate rather than PET, so many microfilms succumb to vinegar syndrome in only a couple of decades), but disks tend to develop problem with stiction in only 10-20 years, and they wear out and fail catastrophically sooner than that if they're in use. Right now the strategy is to copy the digital data to new media every few years, and try to use archival file formats. So we need to do much, much better. But the costs are now so low that a hobbyist can put ten thousand scanned books in their pocket; in an afternoon they can make a digitally-perfect, checksummed archival copy of a thousand books, using a couple of dollars of disk space and BitTorrent. In the microfilm age that would have been impossible for anyone but a librarian, and a nontrivial cost for the library. You sound like you might be interested in https://dercuano.github.io/topics/archival.html https://dercuano.github.io/topics/archival.html, which discusses ways to improve archival, especially digital archival. I think there are some straightforward approaches to