Filed under: On Location
Susan Grinols and her RTI capture team document an Anthropoid Coffin
In October 2009, Susan Grinols – Director of Photo Services and Imaging for Fine Arts Museums of San Francisco (FAMSF), assembled a team of scholars and imaging professionals to document an Anthropoid Coffin with the highlight RTI technique.
Sue and her team members were thrilled with the final results. Using the RTI Viewer, suddenly, hard to decipher glyphs were clearer and easier to view. The curators, interpreters and conservators were shocked at how the RTI technology delivered so much detail, in a completely nondestructive manner.
For a brief look into the RTI capture session be sure to view the flickr gallery.
Filed under: On Location | Tags: caves, Magdalenian, paleolithic, Pyrenees, RTI, UC Berkeley
By Carla Schroer
Mark Mudge and I had the incredible opportunity to shoot RTI and Photogrammetry of Paleolithic material in the south of France. The trip was organized by Professor Meg Conkey of UC Berkeley, a scholar of this region and this material where she has worked for decades. In this pilot project we imaged some engraved plaquettes which are quite difficult to see because of the fine lines and the age of the material (~ 12,000 – 14,000 years old – during the last ice age) We were also able to spend a day in the cave of Marsoulas with local archaeologists Carole Fritz and Gilles Tosello. They have been working in this cave for 12 years sorting out the overlapping fine lines and incredible painted animals and geometric signs found throughout this long and narrow cave. Their work is made more difficult by grafitti over the art in places as well as natural wear and water damage to some surfaces.
Graduate student Tim Gill was also with us on this trip, and will be presenting some of the results of the work at the Archaeological Research Facility at UCB.
It is humbling to stand in a place where such ancient and beautiful art was made. We are thankful for the opportunity and hope that our work can provide additional tools for the people working with this material.
Check out the Flickr Gallery: “Magdalenian Art in the Ariège“
Photogrammetry Environment in a Paleolithic cave in France (L-R): MacBook Pro, 580EX II with gary fong light sphere diffuser(s), Gitzo geared column tripod with a 5D Mark II mounted upside down, another 580EX II (triggered by pocket wizards) and UC Berkeley professor Meg Conkey.
Mark Mudge carefully setting up for an RTI capture.
By Marlin Lum
640ws Einstein monolight – by Paul C Buff
Einstein 640 by Paul C. Buff
Word on the street. We’ve got the good pleasure of knowing, (that some time soon), Paul C. Buff, (manufacturer of our fondly desirable Alien Bee Lighting strobes) will be shipping the Einstein monoblocs.
Many of you might be using the Aliens Bees to as your light source for HighLight RTI captures. If you’re in the market for a monobloc, you might want to look into this unit. Though not yet available, this unit would take you to the next level, improving upon the alien bee line.
The new 640ws monolight seems pretty top shelf. Got features? Good stuff mate.
Just a few highlights:
-Worldwide power compatibility (95-265VAC, 50Hz or 60Hz, autoswitching)
-Full power recycle time of 1.7 seconds at 120VAC (60Hz) or at 240VAC (50Hz)
-CONSTANT COLOR and ACTION modes; one is optimized for colour temperature consistency and the other for stopping motion (uhm, sweeeet, but never throw away your gray card)
-Removable Pyrex flash dome over the flash tube and modeling light (got to love that)
-roughly the same size as the AB 1600, but heavier, bc it’s got some steel in it.
-Illuminated LCD display and push button controls for setting and reviewing of flash functions (don’t get left in the dark)
-The formal official name of this product = “Paul C. Buff Einstein 640“
Release Date
The Einstein 640 release date is (tentative) but due in December 2009 direct from Paul C. Buff at an aprox price of about US$439.00.
Filed under: Technology, Training | Tags: Digital Conservation, Digital Imaging, Workshops
By Debra Dooley, Executive Director, and Marlin Lum, Imaging Director, CHI
We have quite a bit of information on Reflectance Transformation Imaging (RTI) on our website. But what’s the process used to create a RTI? There will be several blog entries on the process. For more detailed information we recommend that you sign up for the Digital Imaging Techniques for Conservation & Education 3-hour workshop. Check out a Flickr photostream of one of the workshops.
There are four different parts to the process: Preparation, Capture, Processing, and Viewing. This blog entry is a high-level summary of the Capture process.
There are two different methods used to capture RTI. One is called Highlight RTI and the other uses a hardware system. CHI calls the custom hardware systems we build “RTI Capture Hardware Systems” and they are usually built for specific types of objects.
Highlight RTI
The highlight method is easy to use in the field as well as in a controlled setting. You use a tripod, digital camera, a light source (strobes or continuous lighting) and other generally available equipment. That’s one of the big pluses about highlight RTI – “over the counter,” pro-sumer photographic equipment will yield professional, museum-quality, high-grade digital RTI surrogates.
This picture was taken after one of the workshops. This is a classic “camera down” or “floor setup,” and is pretty basic. Basics include: a tripod with the camera mounted in the down position, a wireless trigger set (pocket wizards), a 580EXII flash strobe (with a string attached), and a priceless stone tool (insert your artwork here) in the field of view.
Carefully placed next to the object are two round black shiny reflective spheres. When the strobe hits the shiny surface, it produces a “highlight.” Bling! Bling! Software used in processing the images finds the highlights in each image to derive a light position (LP).
Also in this image is a Canon EOS Digital Rebel, tethered to a laptop and being controlled by the Canon EOS utility software. The blue tape minimizes movements and vibration during the capture process. The sandbag hanging from the ball head also dampens the wiggles. Again, though basic, the results are high tech.
Highlight RTI setup
RTI Capture Hardware System
The RTI Capture Hardware System is better suited to controlled settings such as in a museum conservation photo/lab. One benefit of using a rig is efficiency. Think mass production, or in this case, mass-documentation. A RTI rig/dome is extremely favorable if one needs to document a large quantity of similar sized objects: coins, signatures, stone tools, paper samples, paintings, objects, etc. etc.
The most noticeable feature of an RTI Capture Hardware system is the light array — many lights (up to 40) mounted at different angles, all directed toward the center, at the object. And of course the camera is also mounted at the apex of the unit. A PC laptop controls the light sequence and asks the camera to open the shutter when a lamp is on, capturing the image with different light positions.
This capture sequence is managed by open source software that we teach you how to use in our workshops, so you should look into it if this is interesting to you.
The following image is of a custom RTI Capture Hardware System built as part of the Developing Advanced Technologies for the Imaging of Cultural Heritage Objects project. CHI built 2 identical systems, one for the University of Southern California’s West Semitic Research Project and one for CHI.
Processing the Images. After capture comes the processing of your images. Stay tuned for an update on that soon.
Filed under: Technology, Workshops | Tags: Digital Conservation, Digital Imaging, Digital Preservation, News, NMAI, Reflectance Transformation Imaging, virtual archaeology
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.
Filed under: Technology, Workshops | Tags: Digital Preservation, NMAI, Reflectance Transformation Imaging, RTI
–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.
Filed under: Technology | Tags: Digital Conservation, Digital Imaging, Digital Preservation, reflectance imaging, RTI
The United Nations Environment Programme (UNEP) declares World Environment Day each June, making this month a time to focus on how we can improve our environment and our planet.
Our global cultural heritage is a vital element of our environment. Like our natural and physical world, heritage sites and artifacts have been adversely affected by climate change and other negative environmental effects, many caused by human activities.
UNEP has created the Champions of the Earth Laureates Program to recognize the extraordinary efforts made by dedicated researchers and activists to increase environmental protection and awareness.
CHI has been inspired by the UNEP program to create a Heritage Heroes initiative that appreciates people in the heritage community who have advanced the field in so many ways. UNEP recognition categories include science and innovation, policy, inspiration and action, and entrepreneurial vision.
The CHI team can think of numerous cultural heritage workers who deserve recognition in each of these areas and in other categories, too.
However, for our first nominee, we have selected someone who has really led the way in promoting digital techniques to document and preserve cultural heritage.
Tom Malzbender, senior research scientist at Hewlett Packard Labs, has helped the field of digital cultural heritage by developing, refining, and sharing advanced imaging techniques and other processes to digitally document and preserve artifacts.
Listen to him describe interactive relighting in a post on this blog. We hope you agree that he is a heritage hero! Let us know about your heritage heroes by posting comments in our blog.
We are interested in all kinds of heroes — not only those who excel in technology, but also those who inspire others to action — historic preservation advocates, fieldwork fiends, educators, and those working in other relevant fields.
by Michael Ashley
I had the pleasure of being invited to a special congress in Seville this past week. Arqueologica 2.0 is the first international congress on archaeology and informatics held in Spain. The organizers managed to bring together over 200 participants from 17 countries representing over 100 organizations, to discuss and debate virtual archaeology and its role in archaeological practice. I found the congress to be inspirational, exceptionally well run, and mostly a whole lot of fun.
Participants included representatives from some of the most important organizations that work to document, understand, preserve and communicate cultural heritage around the world. In fact, the congress was a truly international gathering of professionals who are passionate about cultural history and memory.
So often, the discussions of computer graphics and archaeology focuses on the divide between technologists and practitioners of the discipline. I was impressed by the efforts of the congress program facilitators to get us to look beyond the fissure and to the mutual benefits of integrating visualization methods into archaeology.
Jane Crawford and Michael Ashley at the opening session at the site of Italica
Throughout the congress, many recommendations and suggestions were forwarded. I mention a few here because they resonate well and I hope we would generally agree are essential to promote the broad adoption of digital technologies in service of archaeology.
Bernie Frischer suggested that future Arqueologica meetings might have workshops to leave behind practical training with participants.
Richard Beacham, co-author of the London Charter on visualization in cultural heritage, called for case studies or pilot projects where we can test ideas and refine procedures in the real world.
Graeme Earl and several others suggested that virtual archaeology methodologies are actually archaeological techniques that must be truly integrated and carried out in archaeological practice.
Mediterranea Project
Many of us were kindly invited to listen to Alfredo Grande discuss the ambitious Mediterranea Project, which seeks to integrate the cultural heritage of the Mediterranean for research and public access and enjoyment. Core to the project is an attention to ‘big blocks’ that are essential to archaeological work practice – documentation and research, conservation and preservation, presentation and information.
One of the highlights of the scientific program was the uniquely organized quick fire plenary session that involved 23 of us lined up in the first row of the auditorium. From the stage, Víctor Manuel López-Menchero Bendicho gave us each <2min. to summarize our opinion on the state of virtual archaeology. This led to a lively debate with many more questions than answers, but there was general consensus that even now in 2009, we are only scratching the surface at the potential for digital archaeology.
Daniel Plentinckx in the spotlight during the rapid fire plenary
Arqueologica 2.0 was the first of what the sponsor organization, the Society for Spanish Virtual Archaeology (SEAV) (also launched at the congress), hope will become an annual event. I hope so, not because the world needs another conference, but because the spirit and enthusiasm expressed by our new friends in Spain is what the world needs.
My favorite quote from the congress was made by a colleague, “It’s more important who you work with than what you work on.” I would work with Alfredo and Victor anytime. I am sure we can find some really important things to do in an enjoyable fashion.
Muchas gracias por todo, nuevos amigos!
Filed under: Commentary, News, Technology, Uncategorized
By Judy Bogart, Technical Writer
NOTE: Judy Bogart has been a CHI donor for several years and now donates her time and skills to help CHI create great training materials. In this blog, she shares what CHI means to her.
As an old friend and colleague of Carla’s, I have been following the progress of CHI since it was a gleam in her eye, and have watched it grow into a well-established and well-respected enterprise with a real opportunity to make lasting changes in how cultural artifacts are documented and preserved in the 21st century.
I find the technology fascinating, with endless possibilities. It is a pleasure to be able to contribute my skills to make this technology more accessible to the people who need it. This is what I do professionally for commercial software, and being able to do it for something with real, demonstrable moral value and social benefit makes me very happy!