RIT Students Discover Hidden Text Using Multi-Spectral Imaging
1 2022-10-23T11:56:24-07:00 Elizabeth Palomino 97f5cc41f822c98012020ee3f1612be0c7950d52 40636 2 Rochester Institute of Technology students discovered lost text on 15th century manuscript leaves using an imaging system they ... plain 2022-11-19T08:47:54-08:00 YouTube 2020-11-18T13:47:33Z YEieepHPMA0 Rochester Institute of Technology Elizabeth Palomino 97f5cc41f822c98012020ee3f1612be0c7950d52This page is referenced by:
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MS 9/2:4 Imaging
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Multi-Spectral Imaging
The fragment at the Spencer Research Library (MS 9/2:4) has a recto and verso with embellished vines around the text. The other pages from this manuscript are spread across different collections in North America. One leaf is in the Cary Graphic Arts Collection at the Rochester Institute of Technology in Rochester, New York. In 2020, students at Rochester uncovered lost text on two 15th century leaves, one of them is a page from the same Book of Hours as MS 9/2:4. The text was recovered by taking a series of photographs under different wavelengths of light, both visible and invisible (ultraviolet and infrared). This technique is known as multispectral imaging (MSI) and it can reveal details that are invisible to the naked eye. When ultraviolet light is applied to an artifact, it is called ultraviolet-fluorescence, because specific chemical compounds fluoresce or glow under UV light. Ultraviolet-fluorescence revealed a dark French cursive that was scraped away from the parchment leaf. There are 30 known pages from this Book of Hours. The other pages could also be palimpsests. [1]
Highlight Reflectance Transformation Imaging (RTI)
At this time, the imaging lab at Spencer is not equipped to capture multispectral data. Instead, we used a form of computational photography called Highlight Reflectance Transformation Imaging (RTI). RTI images are created from multiple photographs of a subject shot from a stationary camera position. In each photograph, light is projected from measured points and reflected back with a black sphere. There are two types of RTI, dome RTI and highlight RTI. The highlight method is a low cost alternative to dome RTI, which relies on a calibrated dome with integrated light points. Domes are often large, their size must be relative to the size of the object, and fragile objects are difficult to place under the dome. The necessary tools to capture highlight RTIs include a digital camera and tripod; a flash gun, flash transmitter, and a tether for the shutter release; a black reflective sphere (we used a black Christmas ornament) and string for measuring the distance between the flashgun and the object. After creating a data set, the images are rendered in RTIBuilder the resulting file is either a .ptm or .hsh file. RTIViewer allows the viewer to take the resulting file and illuminate it with the existing light points.
MS 9/2:4 was selected to determine if RTI could detect lost text and determine whether this manuscript is a palimpsest. In the end, the results were inconclusive. I was unable to identify additional text but the information could still be obscured. If this manuscript is a palimpsest, it may require more robust imaging such as multispectral to uncover lost text.
[1] “RIT students discover hidden 15th-century text on medieval manuscripts”
https://www.rit.edu/science/spotlights/rit-students-discover-hidden-15th-century-text-medieval-manuscripts
