Message-Id: <mailto:199408181523.KAA06560@library.wustl.edu> Date: Thu, 18 Aug 1994 10:49:27 EDT From: Robert Rosenberg <mailto:rarosenb@GANDALF.RUTGERS.EDU> Subject: Re: [Q] Which Scanner for manuscripts To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>
> Using a digital camera would provide the advantage of being able to
> create digital images of any size manuscript, object, or bound volume
> without regard to limitations of your scanner bed size or object
> condition.
>
> I do heartily agree that for my dollar there is nothing yet to beat a
> traditional photographic image. If I were doing a project on fragile
> manuscripts, I would first photograph them in both color transparency and
> black and white (4X5) and then have the transparencies scanned for
> access. With this strategy, you can always re-scan at a higher resolution
> when the qualilty of storage and/or compression improves.
I think the technology is reaching a cusp. There is an example of some digital camera work at the Beowulf project (if you have Mosaic, check out http://www.inslab.uky.edu/e-beowulf; there is an ftp site there, too, I believe). The images were taken with a high-resolution digital camera. Although the full color (24-bit), maximum resolution images are 21Mb (!!), the quality on screen matches or exceeds what could be retrieved from a photographic negative. For an example of that quality, look at any US paper money, $10 or higher, with a "1990" series date (to lower right of the central portrait). You will see two or more lines around the portrait. Examination with a magnifying glass will reveal that the outside "line" is not a line at all--it is "THE UNITED STATES OF AMERICA" in tiny block capitals. The camera used for the Beowulf shots, when imaging the bills, can resolve that onscreen. Simple pixel-to-film-granularity comparisons are not a good measure of resolution comparison.
The preservation problem does weigh heavily in favor in film, but perhaps some cases will be better served by scanning first and then creating film/slides from the images.
Bob Rosenberg | Trying to understand learning by Thomas A. Edison Papers | studying schooling is rather like Rutgers University | trying to understand human New Brunswick, NJ 08903 | sexuality by studying bordellos. mailto:rarosenb@gandalf.rutgers.edu | --Mary Catherine Bateson