About the Project
Project Author
Elizabeth Palomino earned her B.A. in Studio Art with a minor in Public History from Northwest Missouri State University in 2016 and she is working toward her M.A. in Museum Studies at the University of Kansas. From September 2019 - June 2022, she was the Digital Imaging Assistant at KU libraries, where she photographed special collections. Throughout her career, Elizabeth has built exhibitions and helped with art installations. Exhibit design is vital to her role as a museum professional because it is a form of outreach and information exchange.
Digitization
In 2019, I was hired as a Digital Imaging Assistant for the University of Kansas Libraries. I worked at Watson Library part of the time and the rest was spent photographing special collections at the Kenneth Spencer Research Library (SRL). I often photographed collections with the Digitization Coordinator, Sarah Chapman. It was helpful to have a second pair of hands when handling bulky or fragile materials. After image capture, the photographs were lightly processed with cropping and white balance applied. Tasks were split so that one person could focus on capture while the other person managed and edited files on the computer. The act of photographing a collection in a library, museum, or archive is referred to as digitization. The process of digitizing includes adding descriptors such as date, location, and object number. These details accompany an image and are known as metadata.
Medieval Manuscripts
The importance and scope of the manuscript collection at KU
The proposal to digitize the medieval manuscript collection was initially presented to the Digital Initiatives department in February 2020. By March, the project was halted due to the Covid-19 pandemic. By the beginning of the Spring 2022 semester, the digitization project was re-introduced.
Reflectance Transformation Imaging
In 2022 Sarah introduced me to an advanced form of digitization known as Reflectance Transformation Imaging (RTI). RTI is a form of computational photography because it uses computer generated calculations to create a file from an image data set. RTI consists of a series of photos (around 40-60) shot from a stationary camera. In each image, light is cast from a measured angle with a flash gun and reflected on to a black sphere. After the photos are rendered, the file can be opened in RTIViewer and dynamically relit from the captured points.. The idea for an RTI project grew from other proposals that I shared with Sarah at the start of my Museum Studies internship. I was particularly interested in building a digital exhibit. Sarah suggested a RTI project with an exhibit aspect. The ideal candidate for the project was the medieval manuscript collection. Toward the end of March, Sarah and I held a meeting with Angela Andres, Elspeth Healey, and Kivilcim Yavuz from SRL to talk about the benefits of a RTI data set. Sarah and I decided that photographing fragments would reduce the amount of data and prevent the challenges of working with a bound manuscript. Kivilcim chose a box of candidates and from there, we chose five individual fragments with writing on the front and back (recto, verso) of the leaf. As a bonus, we photographed the front and back cover of MS C189, a manuscript bound with recycled fragments.
Image Capture
The capture process took three days and around fifteen hours. Combined, there are 711 photographs, with each image set containing an average of 60 photos. Each manuscript contains the original .dng (digital negative) files and .jpg exports (needed for RTIBuilder) bringing the total number of photos to 1,422 and 53 GB of space. A difficult part of the capture process was deciding the best angle and position to hold the flashgun. I held the flash gun at four angles including an angled overhead shot and a raking shot where the flash was low, almost parallel to the manuscript. I moved around the copy stand in a circular motion and placed myself and the flash gun at 12 positions relative to the manuscript. The position of the camera in relation to the copy stand required me to photograph while squatting on the ground. I remained still and held my position with the flashgun until the shutter was triggered.
RTI Render
Despite the time commitment, image capture was the simplest part of the process. Downloading the RTIBuilder from Cultural Heritage Imaging (CHI) required a lot of trial and error. To begin with, the security settings on my 2015 MacBook Pro mistook the download for a malicious file, so I selected “allow apps from CHI.” When this didn’t work, I temporarily disabled my firewall. It seemed that the application was downloaded, but when I clicked on the rtibuilder.exe file it didn’t run. I searched the CHIforums for an answer and I realized that RTIBuilder will not run on anything later than 2018 High Sierra OS. My second option was to try the software on a 2014 HP Envy. Again, I selected “allow apps from CHI” and I temporarily shut off the firewall. No luck. I realized that I needed to install Java to run the program. Finally, after many attempts, RTIBuilder opened. Downloading RTIViewer was relatively easy, all I had to do was check “allow” and briefly disable my firewall.
Before importing the photos into RTIBuilder, I opened the .dng files in Adobe Bridge and rotated image sets and batch applied white balance using the eyedropper tool on the color check. Once all the adjustments were complete, I saved the files as .dng and .jpg. There was minimal processing to the image files and no color adjustments other than white balance. After processing, I created nested files in my C drive with specified file names. This step is crucial because the software cannot locate the files if they are not named to the builder’s specifications. The files must be named jpeg-exports and original-captures. I followed the instructions and waited for the render. Instead, I received an error message. After some forum searching I found that I had to download the PTMfitter plugin (polynomial texture map), which is needed to generate .ptm files. The builder is also capable of generating a .hsh file. However, both the ptm and hsh plugins were not embedded in the download and I was only able to find the PTMfitter through a file that was shared in the forum thread. I tried again and received another error message. Sarah referenced a different guide and her old RTI files to confirm that the files would not render because they were incorrectly saved as .jpeg’s following CHI’s instructions. The files were reformatted as .jpg and Sarah ran them through her 2012 Lenovo computer. The render worked this time. I still didn’t have a workable RTIBuilder so Sarah suggested that I try the RTIbuilder[Console].exe instead of the RTIbuilder.exe application, both were included in the software download and she had used the [Console] version with success. I tried it and after some waiting the file rendered successfully. After all this work, it was exciting to see the end result.
Cost Benefit
In closing, I have to reflect if this process is worth the time commitment. Cultural Heritage Imaging needs funding for critical software updates. A post by CHI founder Carla Schoerer from this year, confirms that they have secured funding for updates to the RTIBuilder. There also needs to be edits to CHI’s guide to correct mistakes and include missing information, such as image scaling for .jpgs in the builder. As a whole, there is a limited understanding of RTI files and their benefits to object research. If RTIBuilder and RTIViewer were easier to download and use, it would generate interest among researchers. There are very few people who are trained in this process. Image capture is tedious but with practice it is not difficult. Instead, it is the constraints of the RTIBuilder that create frustration. It is a shame because this is a useful tool that allows researchers to explore manuscripts under multiple lighting conditions. The image capturing tools (flash gun, receiver, string, reflective sphere, camera, tripod) are relatively inexpensive and it is a non-invasive imaging technique.