Closing Statements
Throughout this process, I have asked myself if RTI is worth the time commitment. The benefits are that the tools (flash gun, receiver, string, reflective sphere, camera, tripod) for highlight RTI are relatively inexpensive and it is a non-invasive imaging technique. The photographic process is tedious but with practice it is not difficult to capture a RTI data set. However, there needs to be edits to CHI’s guide to correct mistakes and include missing information, such as image scaling for .jpgs in the builder. Overall, it is the constraints of the RTIBuilder that are frustrating. Cultural Heritage Imaging (CHI) needs funding for critical software updates. In a recent post by CHI founder Carla Schoerer it is confirmed that they have secured funding and they are collaborating with Visual Computing Lab in Pisa to create a new software called RelightLab that will replace RTIBuilder. The University of Southern California (USC) has an imaging lab that is devoted to dome RTI. They also use a RTI builder and viewer that they developed, instead of CHI's open source programs. Because USC has their own source code, they are not restricted by RTIBuilder's infrequent updates. As a non-profit CHI is doing the best they can with limited funding. For a small staff, they are quick to respond and they actively engage in outreach. The team offers consultation services and organizes RTI workshops for museums and universities around the world. The amount of resources related to RTI is very small. There are few experts and as a result, few publications about this process. As a whole, there is a limited understanding of RTI files and their contribution to object research.
For the researcher, RTI is a useful tool because it encourages exploration through multiple lighting modes. Typical digitization relies on even lighting, which obscures surface inconsistencies and flattens the appearance of an object. Some details, such as worn and damaged text are difficult to see when photographed with traditional studio lights. An example is MS 9/2:16r, a leaf that has water damage in the center of the text. The water has washed away the ink, so that it is nearly impossible to read individual letters. RTI allows the viewer to look at this manuscript with ideal lighting and contrast. As a result, it is possible to detect letters on this manuscript, depending on the light, and how it falls on the page. With MS 9A:5 a thin, translucent paper was adhered to the bottom of the page to strengthen the worn parchment. This is a modern repair that is easily detected with RTI. MS 9A:4 has less visible repairs because they are spot applied throughout the leaf. RTI enhances the surface ripples and hard point ruling in MS C189. Hard point ruling was often used to mark the margins and baseline for the text. It is produced with a sharp metal tip and it is nearly invisible with traditional photography. Hard point ruling is a significant feature for researchers because it shows manuscript production techniques and stylistic choices among scribes. With certain manuscripts, such as MS 9A:4, it is possible to see hair follicles, which helps determine the hair side and the flesh side of the parchment. Sadly, I was unable to use RTI to determine if MS 9/2:4 is a palimpsest like its sister leaf in the Cary Collection at Rochester. I initially thought that RTI would show indentations and outlines of letters, indicating where the ink was scraped away. This can be difficult because a pumice stone was often used to smooth the parchment after the text was removed.
RTI has limitations. It enhances surface details that are present in the object. However, it is more difficult to detect elements that were purposefully erased. This includes removal by scraping and burnishing a surface. With decorations or paintings, it can involve painting over sketches. Multi-spectral imaging is useful because it captures visible and invisible light waves such as infrared, and ultraviolet (UV) light. This wide range of light is helpful for detecting elements such as repairs, underdrawings, and palimpsests. The downside of multi-spectral imaging is that infrared and UV light are especially damaging to collections over time. In contrast, RTI uses a short burst of visible light to illuminate an object. From a conservation stance, this burst of light is relatively harmless.
Future Outcome
In the last year that I worked for KU libraries Sarah proposed and received funding for new imaging equipment. Late September 2022, a new copy stand and Phase One camera were delivered to the KSRL imaging lab. The copy stand is the Versa model from Digital Transitions. Previously, the camera was attached to a copy stand arm that was manually raised and lowered on an affixed pole. The base of the copy stand consisted of a wooden platform with wheels. The platform rested approximately a foot off the ground. The Versa copy stand eliminates the need to squat. It also has a built-in book cradle that allows the user to safely digitize bound materials. The new Phase One camera is built specifically for cultural heritage imaging, and the Capture One software is suited for high volume digitization, instead of fine art photography. The updates will make the capture process more streamlined and efficient. With the addition of new equipment in the KSRL lab and funding for the new RelightLab, it is my hope that RTI imaging can continue at KU. Perhaps, other advanced imaging techniques will be introduced into the development of future projects. I am optimistic that my project will spur funding for advanced imaging at the Kenneth Spencer Research Library and the University of Kansas.