Cultural Heritage Imaging

–Mark Christal, NMAI Multimedia Coordinator

Teachers have an old adage about the best way to learn something is to teach it. My colleague, Kevin Cartwright, and I had that concern about Reflectance Transformation Imaging (RTI), because the National Museum of the American Indian had joined the NPCTT grant with the role of assisting with the production of educational materials on RTI and Photogrammetry techniques. Fortunately, we got the opportunity to learn RTI in a four-day workshop on June 8-11 at the Smithsonian Cultural Resources Center in Suitland, Maryland, under the tutelage of Carla Schoer and Mark Mudge. CHI photographer Marlin Lum came to document the training and lend his own expertise to the classes. Michael Ashley arrived on the on the third day to talk about the new techniques for managing metadata.

The CHI instructors and staff were brought to Washington, DC by Carolyn McClellan, who is a relatively new Assistant Director at the National Museum of the American Indian (NMAI) heading up the Community and Constituent Services department. Carolyn first learned of CHI when she was working at the Bureau of Land Management. She participated in the digital documentation of rock art at Legend Rock in Montana. The project utilized close range photogrammerty techniques under the direction of BLM staffers Nefra Matthews and Tom Noble. Carla and Mark directed the RTI captures of some of the same features. These four experts will be teaming up again in the upcoming NPCTT training session at the Presidio in San Francisco on July 23-24.

We had contracted for a 12-seat class from CHI, and a variety of specialists at the Smithsonian attended. In addition to myself, Carolyn and Kevin, community liaisons Robert Alexander and Caleb Strickland and four photographers from the NMAI photo services department headed by Cynthia Frankenberg participated. Melvin Wachowiak, a conservator from the Smithsonian Museum Conservation Institution, attended with great interest. A recent intern of Mel’s, Rebecca Mendelshon, joined the training, too. We had two attendees from Smithsonian Exhibits Central, Vince Rossi and Adam Metallo, who have a keen interest in digital modeling.

NMAI conservator Emily Kaplan proved to be a very important contributor to the class. Emily is qualified to handle NMAI collections, so she was able to bring in the museum RTI subjects that are a focus of current research or being prepared for upcoming exhibits. These included Mississippian copper pieces, Mayan jades, a decorative Mayan carved panel, an Aztec stone carving, and several Incan qeros (ceremonial goblets). Emily was very excited to utilize RTI imagery on the qeros, because they have been a research focus of hers for nearly 10 years.

The workshop went extremely well, and all participants received a through grounding in RTI concepts and techniques. The experience well informed Kevin and I for our Friday session of shooting an educational clip on RTI capture. We brainstormed the approach with Michael Ashley, and we decided to write up a shot list that closely followed the “Guide to Highlight RTI Image Capture” document developed by Carla and Mark. By doing so, the instructional video and document would reinforce each other. Mark and I became the “talent” for the shoot, with Mark moving the camera strobe to each hemispheric position while I played the role of string master who assures that each lighting is done from the correct distance and angle. Carla triggered each shot in the sequence from a laptop that communicated with the camera. Kevin was our videographer and Michael read out each shot on our shot list to provide a slate for the editing tasks. We hope that the experience of creating this short educational video clip will help CHI document other aspects of RTI creation.