By Sophie Bacchus-Waterman, Special Collections Photographer
As the imaging phase of St John’s digitisation project gets underway, I thought it was a good time to introduce my role in the project, and give a behind-the-scenes look at what it takes to digitise books from the imaging side of the project (for information on the metadata, see this past blog post.)
As Special Collections Photographer, I will be using a Grazer Conservation Cradle and OnePhase Camera XF/ IQ4 100 Digital Camera System with an 80mm Schneider-Kreuznach Blue Ring LS lens, a flatbed and wall-mounted Canon 5DS + 35mm lens, and CaptureOne software to take high-quality images of the Western medieval, early modern, Greek, Hebrew, and Arabic and Persian manuscripts, and other 2D items from the Library’s Special Collections which have been chosen for this project. This will take place within the dedicated digitisation studio in St John’s Library and Study Centre.
For this post, I will talk through the equipment I will be using most frequently – the Grazer Conservation Cradle, camera, and CaptureOne software.
The basic idea of digitisation is to create, as close as possible, the experience of seeing a book in person. Obviously, a digital copy of a manuscript cannot replace the act of sitting with a book in front of you, but, as far as possible, digitised surrogates need to be as visually similar to their physical copies as possible. But how is this achieved?
Grazer Conservation Cradle and Laser
For those not privy to the jargon of the digitisation world, a Grazer Conservation Cradle (named after the University Library Graz in Austria, where its developer, engineer and former conservator Manfred Mayer worked) is a large V-shaped stand onto which the book being digitised is placed. The stand is covered in felt, which is in turn covered with black cloth, to keep the binding of the book safe. The cradle is set to a 120° opening angle, and is not able to be adjusted. This is the widest safe opening angle for a book which will not damage its binding. For books which will not safely open to this angle, foam blocks are placed onto the cradle to support the binding at whatever angle it is comfortable.
Along the top of the facing side of the cradle (the side which will be photographed) there is a vacuum bar. The vacuum bar is covered in cloth, and the page due to be photographed is placed onto it. When the vacuum bar is switched on, it acts literally like a very gentle vacuum and lightly holds the page in place. The strength of the suction can be adjusted with a dial, and it is important to use the minimum suction necessary to hold the page in place, so as not to cause any damage to the page.
The cradle can be adjusted to move horizontally and vertically. This allows me to position the page being photographed directly parallel to the CaptureOne digital camera, allowing for the clearest shot. In order to make sure the page is parallel to the camera, a laser light is utilised. If the page is in the correct place, the laser will be visible across it.
Camera and Lamps
Like the cradle, the camera can also be adjusted to move horizontally and vertically. This means that I can get shots closer and further away from the book being photographed, and make sure that everything is in the shot. Once the camera is positioned at a certain distance away from the book, it does not move closer or further back, only vertically, so that every shot is taken from the same distance. As I move through the book, the camera is moved vertically to maintain consistent shots. All of the rectos (right pages) are photographed first, then versos (left pages), or vice versa, to avoid unnecessarily handling the book.
There is a remote control (rather like the ones used by photographers in the Victorian times) which, when pressed and held, can adjust the focus of the camera. When pressed quickly, it will take a shot, at which point the two lamps on either side of the cradle flash, and the photograph appears on the CaptureOne software.
Everything works in tandem. The cradle and camera move, while the book remains stationary. If the cradle and camera have been set up correctly, I should be able to work through the book and get clear and consistent shots by adjusting the cradle and camera slightly as I go. The laser helps me to make sure the page being photographed is positioned correctly. The lamps allow me to make sure the colours in the shot are consistent, and are as close to those in the physical book as possible.
Once the photograph has been taken, the CaptureOne software allows me to make any edits necessary.
The software allows me to zoom in on certain parts of the page to ensure that it is in focus. If an image is not in focus when zoomed in, it needs to be retaken. This really reveals every detail of the page, and allows me to see things which could not be seen with the naked eye.
The software also allows me to add guidelines which ensure that each page is aligned. This keeps each shot relatively consistent, and alerts me when a page is wonky. Obviously, the nature of some manuscripts means that their pages are not always perfectly straight, but the ruler running along the vacuum bar allows me to make sure pages are as straight as they can be, as well as allowing the viewer to see the size of the book being photographed.
A number of other items typical to Special Collections handling are also used during the photography stage. Out of the shot, there may be a snake weight holding down the page that is not being photographed. If a snake weight won’t do the trick, we also have a fabric strap which is secured to the cradle with clips, which gently keeps the pages from closing.
For books which need a little more support, foam blocks are used to keep them at a safe opening angle.
Black interleaving cloth is placed behind each page being photographed. This helps to show any imperfections in the page, such as holes and tears.
Ultimately, everything that happens during the digitisation process is done to both get a clear shot of the page you’re photographing, and make sure the book is safe. Some books will be trickier to photograph than others. They might have narrower margins where text runs into the gutter, a tighter binding, a smaller opening angle, fragile pages, or illuminations with flaking pigment. Each book must be treated as a unique, living, object, with needs that must be met during the photographing process. All of the equipment utilised during the process allow us to capture these beautiful and unique objects, and share them with a wider audience.
- Behind the Lens | Early Irish Manuscripts: https://www.tcd.ie/library/early-irish-mss/behind-the-lens/
- Digitising Medieval Manuscripts: Common Challenges in the Studio and Insights into Using the Conservation Book Cradle: https://www.tcd.ie/library/manuscripts/blog/2021/12/digitising-medieval-manuscripts-common-challenges-in-the-studio-and-insights-into-using-the-conservation-book-cradle/
- Imaging Techniques at the Bodleian: http://bav.bodleian.ox.ac.uk/news/imaging-techniques-at-the-bodleian
- Photography at the Bodleian: http://bav.bodleian.ox.ac.uk/news/photography-at-the-bodleian