Cultural Heritage Imaging

Reconnaissance. Scouting. Preparation. by marlinlum
June 22, 2012, 7:41 pm
Filed under: Commentary, On Location, Workshops | Tags: , , , ,

Reconnaissance. Scouting. Preparation.

Marlin Lum here. Imaging Director at Cultural Heritage Imaging. This blog entry inspired by Mark Christal, strong man and multi-media super genius employed by the National Museum of the American Indian (NMAI) at the Mall in Washington DC. It’s part of his professional game to find out as much as possibly about a topic and then present it to the public via modern visual technology. Go to the National Museum of the American Indian and check out what they are putting out in the world, really good stuff.

River Bed Pano

panorama photograph: scouting for rock art in a river bed

Mark is a graduate of CHI’s 4-Day RTI Training and a NCPTT Workshop participant where he not only refined his skills in RTI capture but also learned about photogrammetry. Aside from being a respected technologist and dedicated vegan, he is also an enthusiast of ancient Rock Art. (no- not album covers). Native American rock art.

Taking his Panorama and RTI capture skills in the field, (meaning a 14 mile mountain bike route, hot weather, lots of photo gear on back), Mark and his crew (also (former) NMAI super genius Video Master, Kevin Cartwright) entered the wilderness on a reconnaissance mission. Mission: to locate a petroglyph, shoot a Pano and scout it for future RTI capture.

I also have to mention, as stated by Mark, ‘that the park ranger had never heard of this (culture) site’. Mark and Kevin only found it after actively looking/hunting, and having followed a good tip from a kayaker. According to Mark, ‘this might be the only known on-site rock art in Maryland’. Mark goes on to say that, “The only other site (Bald Friar) was dynamited in the 20’s because it was about to be flooded.  Parts of that site are now spread across the state in a number of museums and culture centers”. Uhmm. Can you say, ‘sense of urgency’, get out there and document people!

A long time ago I used to work in Hollywood where I knew a location scout. It was his job to discover everything, everything about that location and bring that information back to the unit. His checklist asked questions like: Where is this on the map? What direction does it face? Where is the afternoon sun? Can I get a crew here? Do I need extension cords? Whats the scale of the artwork? What lens do I need? Is my tripod in dirt or water? Who’s land is this? What’s the deal with the roaming horned bull? (true story btw). And where is the crew bathroom?

You get my point. The more you know about your subject (and its owners {past and present}, the better). A thorough knowledge base about what exactly you intend to RTI is essential for creating a successful final product. It’s like anything else, knowing what equipment you’re gonna need (and what you don’t want to carry {or bike} for 14 miles) is gonna make or break it (your back that is).

Hollywood crews might research and setup a shot for months, only to have the actor whisper his lines in 40 seconds.

I will draw a conclusion to this blog and just point you to the large JPEG that Mark Christal email me from his Recon mission into the hot sun. (For those of you shooting in the comfort of a photo lab, you will have your chance.)

Mark’s Recon Pano gives us a glimpse into the beauty, the full shade during full sun, the water level during that time of year, the artwork and the scale (note calibration stick). And for those of you who are curious, yes, this location IS top secret, so, no use in hacking or looking. One last thought, shoot a capture when the water is running low.

Scout and be happy!

check out the flat pano image here on Flickr! Click on the Hi-Res image – can *you find the rock art? (look for the calibration stick)

Go directly to a large the jpeg:

CHI’s National Park Service Workshop by cdschroer

By Carla Schroer

The National Park Service’s National Center For Preservation Technology and Training (NCPTT) workshop was a great opportunity for the instructors as well as the participants. First, Mark and I got to spend a couple of days with Tom Noble and Neffra Matthews (from the Bureau of Land Management) prior to the workshop.

Tom and Neffra are extremely knowledgeable photogrammetry experts with lots of field experience. They also keep up with what’s going on in that field in terms of new products, and new features in existing products. They are a tremendous resource, and happy to share their knowledge. CHI welcomes any future opportunities to work with them again.

The next opportunity for me as an instructor was to hear from folks that participated about their own experiences in the field. A few had tried reflectance transformation imaging (RTI), others photogrammetry, others laser scanning, and all had done photographs and drawings (or been part of projects that did that).

The workshop afforded opportunities to discuss practical issues in the field, as well as get an understanding of some of the challenges people face, and what they are willing to do to overcome the challenges. The group worked well together, shared ideas readily, and asked good questions. I think we all got a lot out of the interaction. It wasn’t just instructors passing knowledge to students, and I really appreciated that aspect of it.

It was also fantastic that we had a range of people with a wide variety of  experiences participating. Having Professor James Davis from the University of California, Santa Cruz attend the full workshop was really valuable, because he could hear directly the issues people face, and share his perspectives as a computer scientist.

James has worked with RTI for some years, and is also well versed in a range of computer graphics techniques, including laser scanning, structured light scanning, and other forms of capturing 3D geometry. He was really interested in the challenges in the field, and what takes the most time and is the most painful about the capture process, always thinking about ways he might be able to remove some of the time consuming parts.

Overall the experience was lively, interactive, open, and fun, but we made serious progress, too. I think it added a lot to have folks staying at the Presidio and getting to know each other in the evenings. Several people mentioned how the opportunity for them was in not only getting access to the technical information, but interacting with other participants.

I think that no matter how good we get at training people with web- based materials, there will always be a place for human interaction and sharing. It was a rich experience, and I truly thank everyone involved for participating fully.


Cultural Heritage Imaging’s RTI Training at the Smithsonian Institution by cdschroer
July 17, 2009, 10:58 pm
Filed under: Technology, Workshops | Tags: , , ,

–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.