In the Spirit of Gutenberg, Treasures for
RARE books like the Gutenberg Bible are usually squirreled away in private libraries or locked in sealed cases in public institutions, where only a relative few people are able to peruse them.
As part of an effort to make its holdings more accessible, the Library of Congress has allowed its copy of the Gutenberg Bible - a 15th-century treasure worth at least $30 million and one of three "perfect" copies in existence - to be photographed digitally and made available on a set of CD's.
Now anyone can examine each of the Bible's nearly 1,300 pages in Portable Document Format. The $80 CD set, which became available in July, makes it possible to zoom in on the elaborate text and the decorative rubrications - the hand-colored letters that mark the beginning of chapters - or click on a Latin word for its English translation.
"We're making available one of the least available books in the world," said Mark Dimunation, the head of the library's rare book and special collections division.
Over the past decade the library has been carrying out a major digitization project to make accessible some of its vast collection of film, letters, photographs, manuscripts and diaries related to American culture. The project's Web site, American Memory (memory.loc.gov), has more than eight million images of American historical materials.
When it comes to books, though, the library is digitizing only its rare books, working with Octavo, a company based in Oakland, Calif., that specializes in high-resolution digital imaging. The library receives a royalty from sales and copies of the digital images. Octavo was started six years ago by John Warnock, a co-founder of Adobe Systems, who became interested in digitizing as a book collector.
Octavo (www.octavo.com) has worked with other major libraries, including the New York Public Library, and currently offers 37 digitized books in addition to the Gutenberg Bible. The company has created software that allows the digitizing of "greater numbers of pages, faster and less expensively," said its chief operating officer, Czeslaw Grycz.
The company's best-known offering, a 15th-century Book of Hours, is also in the collection of the Library of Congress. Octavo, which has a photography studio at the library, has so far digitized 15 of its rare books and is in the process of completing another 10.
Octavo's team spent months planning how to photograph the Gutenberg Bible, which spans three volumes, in a minimally intrusive way, said Hans Hansen, the company's photography director. Only 160 to 180 copies of the Bible were printed by Johann Gutenberg of Mainz, Germany, and the library's copy is one of about 50 known to have survived. The library acquired the Bible in 1930 and displays one volume at a time on a rotating basis in its Great Hall.
The photographers spent four and a half months on the project in 2002. First a special cradle was built to keep the books free from chemicals that could interact with their bindings. Printed on vellum, a writing surface made of calfskin or sheepskin, the Bible must be stored in an extremely narrow temperature range. Only cool metal halide lighting was used to keep the room temperature no warmer than 70 degrees.
Because the pages were not numbered, photographers took great care to ensure that no pages were missed. Library employees handled the book, turning the pages and returning the volumes to their secure location after each session.
Using a 132-megapixel camera system with a Danish-made Phase One digital scanning back, and shooting from above for the best light, the photographers recorded each set of facing pages. Each spread took about six minutes to scan, while a monitor measured whether the color was accurate. As the images were recorded and stored, they were sent over the Internet to Octavo's offices.
"We could zoom in and see the book at 600 percent, so you can see every single itsy-bitsy detail," Mr. Hansen said.
It took almost a year to match the English translation column by column to the Gutenberg Bible. The CD set also includes a scholarly analysis of the text and information about the Bible's collation, binding and provenance.