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On the road to the Universal Library - at Oxford
What do you do if you have a decentralized library system with over 100 collections that together probably represent the largest assemblage of original material anywhere?
If you are Oxford University, you set yourself the ambitious goal of creating a Digital Library that can provide researchers from their home locations with centralized easy access to these collections. This is not just a matter of creating a digital catalog of what is contained in the various collections, but actually providing digital images of a quality that will satisfy most of a researcher's needs. This ambitious goal was set in 1999 with the publication of 'Scoping the Future of the University of Oxford¹s Digital Library Collections' funded by the Andrew W Mellon Foundation and compiled by Stuart Lee, Head of the Centre for Humanities Computing, University of Oxford.
The report's goal was to research the current level of ongoing digitizing of original material,determine how to migrate individual projects into a centralized system, develop selection criteria and ascertain new directions. In their conclusion they defined a need to establish a digital service group which would not only be capable of state of the art digitizing of delicate original material, but also assist the curators in developing the technical means to define their digital collections and to manage the visual information thus created. This service group became known as the Oxford Digital Library of the Oxford University Imaging Services.
In June 2000, Norbert Lossau was made the director of the Oxford Digital Library. With his experience gained during the digitization of Gutenberg's Bible by the Goettingen University, he brought extensive knowledge of scanning delicate material. After reviewing the existing situation, it was decided to call a halt to imaging services for a period of two months. This was to provide time to carefully research and acquire the best equipment for the work, establish procedures and standards and set up systems to aid in the executing of the workflow. I have just come back from a visit to their digital studio and can report that they are once more up and rolling.
The Digital Library's studio has four major scanning stations. One station is a a bitonal scanning station which uses the Zeutschel Omniscan 7000 (7500 pixels CCD), which they have recently acquired. As there is no color involved in bitonal work, they have felt comfortable leaving this machine in a Windows environment. I was personally intrigued to see that they were using ACDSee on this machine. They said that they were using it because its viewer was so fast. To me it symbolized an attitude to use whatever did the job best, simply and cost effectively, because the Studio has to not only produce excellent image files without damaging the original material, but also do it as quickly has possible. They have a large collection to put online.
The other three stations, which are used for color work, include G4 Apple computers equipped with 1GB RAM each. These color stations use large format cameras (4x5) but instead of film backs have scanning backs by Phase One and BetterLight. Digital scanning backs are fairly common in professional studios these days and are a very logical choice for those who are creating digital images for the purpose of access and preservation of objects and sensitive material. They produce very large high-resolution files, are capable of capturing good color information, and are flexible in their positioning. This flexibility is important when photographing sensitive material which may not easily be placed flat and parallel to the picture plane.
To hold this sensitive material, archivists, who have been photographing their material for sometime, have developed an assortment of cradles. These cradles adjust both the size of the opening for the spine of the binding and also the rotation, so that there is no stress applied when pages are placed in the proper positionrelative to the camera. Many cradles or stands are being developed which are quite beautiful and ingenious. The ODL is currently using two such cradles which were developed at Oxford. In May however, they will be replacing one of their own with a cradle developed by Manfred Mayer of the University Library of Graz, Austria. This cradle has an ingenious arm which hold a page in the proper plane by means of light vacuum pressure. When the scanning is complete, it lowers that page and then raises the next page.
Scanning backs do require longer periods of exposure to the original material than film backs do and high levels of light, all of which can have an adverse affect on sensitive material. The cradles help prevent too much stress on the material when positioning and filters can lower the heat and UV exposure of the light. The third station which is used for capturing images of large format items not requiring cradles, has been set up with six times the usual lighting level, which has reduced the scan time. The filters which they use to lower the heat, were very effective. In fact it was remarkably cool for the brightness created.
As I mentioned earlier part of the process during "the stop the presses time" was also to establish standards and procedures. An example of these procedures, which I saw, is the scanning of a color chart by GretagMacbeth and scale with the first scan of each shoot and or at the beginning of each project. They also calibrate their monitors every two months. The one I saw had been calibrated last week and was right on to the color chart being scanned.
It was all very impressive, not only the Scanning studio itself, but the very enterprise which they are undertaking. We wish them well.
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