The manuscripts and early printed books chosen for the Polonsky Project are all extremely valuable items from the libraries’ special collections; some of them are more than a thousand years old. Their deteriorated binding and parchment leaves require very careful handling, meaning that ordinary mass-digitization equipment (such as the high-throughput automated scanners used by Google to digitize 18th- and 19th-century books) is out of the question. The materials being digitized here also require high-quality images, as scholars are interested in every aspect of the physical page. In order to record every detail, and to showcase the beautiful illuminations and woodcuts included in many of the items being digitized, it is necessary to capture full-colour, high-resolution images in every instance. While the digitization departments of the Bodleian and the Biblioteca Apostolica Vaticana are used to working at these high standards, it is virtually unprecedented to do so on such a large-scale project.

In order to adhere to these standards while staying on schedule, the Bodleian and the Biblioteca Apostolica Vaticana have assembled a combination of highly trained staff and state-of-the-art equipment. This post will focus on the equipment and techniques being used by the Bodleian.

For this project, the Bodleian’s imaging tool of choice is the Conservation Copy Stand 6545, known as the Grazer Conservation Cradle. This formidable Austrian-made device stands 2.7 metres high and combines a 60-megapixel overhead camera with an adjustable book cradle and a suction device to hold the pages flat. The Bodleian now owns two Grazers, which will be used primarily for fragile or illuminated items. For smaller printed books, they will be using the Atiz BookDrive Pro, which has a cradle with a fixed opening of roughly 100 degrees and two 22.1-megapixel cameras, meaning that both verso and facing recto can be captured at once.

The Bodleian’s imaging studio is currently located in the same building that houses the conservation and digital systems departments. The imaging itself takes place behind thick black curtains in order to control the lighting of the manuscripts. The Bodleian employs a team of four experienced imaging technicians, all of whom have worked in the studio for a minimum of six years; when they are not working on the Polonsky Project, they fulfil image requests for academic or commercial use.

There are no shortcuts in the imaging process; each page has to be photographed individually and turned by hand. In fact, when using the Grazer, each page has to be turned twice; rectos are photographed the first time through, versos the second. The technicians do not use gloves, but they do handle the leaves very carefully, and they use the adjustable cradles or foam supports to make sure that the binding is not damaged. The first page of each book is photographed with a centimetre scale and a colour target alongside, so that viewers can see how big the book is and image editors can make sure that the colours are correct. Every 30 or so pages, a sheet of black paper is inserted between the leaf being photographed and the previous leaves; this is called ‘interleaving’, and it ensures a crisp image of the current page. Interleaving is also done for any leaf that is torn or perforated or irregularly sized, so that these details are preserved in the final image. As they progress through the book, the technicians check the focus of the camera to accommodate the changing page height. Once an image has been captured of each page, and of the upper and lower covers and the spine, the technicians assemble the images in sequence on their computers and do any necessary cropping or colour adjustment before passing the images on to digital services staff for processing.