Greetings from the OSU Libraries Preservation & Reformatting Department, Digital Imaging Unit. The department is dedicated to cultural heritage imaging, an umbrella term for scanning and photographing historical materials. If you’re unfamiliar with our work, check out one of my previous posts for some background on what we do.
Digital imaging allows libraries to share rare and unique materials with a worldwide audience, increasing the visibility of collections while protecting the original objects from excessive handling. The goal is to capture images that reveal the significant details of rare books, manuscripts, artifacts, and other materials, giving researchers the next best thing to seeing the original. Today’s post shows some examples taken from the library’s collection of Medieval and Renaissance manuscript fragments.
High-quality image capture is important for several reasons:
- Manuscripts contain small details such as fine handwriting, brushstrokes, illuminated letters, and illustrations. Researchers who cannot examine the items in person can instead zoom in to images shared online. For details to hold up under zooming, the digital images must be taken with a camera that has a good lens and a high-resolution image sensor.
- The texture of the parchment may be of interest. Experts can look at the texture and tell you what kind of animal skin the parchment was made from. Wrinkles, stress lines, and holes or tears can reveal something about the manuscript’s use. Below is a detail of a page that was once bound in a book–the tears at the right show where it was sewn into a binding–though now it survives only as a fragment.
- Old repairs can also be shown in detail.
- The physical deterioration of a manuscript may reveal the types of materials used in its production.This detail shows places where iron gall ink has eaten through parchment:
Manuscripts are usually photographed on a copy stand–a table with a camera mounted overhead.
In this way, digital copies can be made without harming the original, often fragile, item. Some manuscripts require special photographic equipment or lighting setups. I’ve provided a couple of examples below.
For especially small manuscripts with fine handwriting, a macro lens is sometimes needed. In the images below, I’ve zoomed in to a 1/2-inch detail of a manuscript. The image on the left was taken with a normal lens, the one on the right with a macro lens.
Macro photography improves online viewing of items with very small illustrations and brushwork. The original manuscript shown in the image below is just under 4 inches wide by 5.5 inches high; the detail of the illuminated “e” is 1 inch wide. Using a 120mm f/4 macro lens to photograph the page makes the writing and the illustration easier to see.
Illuminated letters are a well-known feature of Medieval and Renaissance manuscripts. Often they include vivid color inks, and gold leaf or other metals. (More information about these materials and methods is available here).
Photographing these pages presents the photographer with a lighting problem. Normally we light across the page, with lights placed wide at either side of the copy stand, in order to ensure even lighting throughout the image.
The problem is, this lighting setup does not reflect the metals, making them look flat and brown, almost indistinguishable from the ink next to them. A researcher studying the manuscript online would not know where the gold leaf and other reflective materials are.
The solution is to use a setup called axial specular lighting. Lights are placed high and close to the camera, nearly in line with the axis of the lens.
This brings out the specular highlights in the gold leaf.
Specular lighting also shows the differences between various metals used on a single page.
It reveals places where the gold leaf has flaked away…
…or perhaps been deliberately removed at some point in the past.
Because the requirements of cultural heritage photography are so specific, it can be difficult to find instruction on how to do it. A great place to start is the AIC Guide to Digital Photography and Conservation Documentation, available for purchase from the American Institute for Conservation.