Preservation Photography: Roles and Rules

By Karen Price

There’s something about a photograph. Humans are visual and I think pictures can sometimes reach broader audiences than can words. 21st century technology has only helped our addiction to the visual with the advent of digital technology and social media platforms. Digital cameras have now made the photographic process quicker. Yet, their user-friendly, high-quality format as well as their instantaneous outcome has, on the downside, introduced a cult of point-and-shoot photography.

Figure 1: Nine grave shafts exposed during the Mount Vernon Slave Cemetery Survey. Karen. E. Price, Mount Vernon Archaeology.

This is where I was at until around three years ago when I came to Mount Vernon for an archaeology internship. After having a lecture on artifact photography and a project that involved a digital portfolio, I attempted through trial and error to become an artifact photographer for the Archaeological Collections Online project, a two-year endeavor to digitize important finds from the Washington households’ 18thcentury midden. This necessitated taking the camera off automatic, learning about aperture, ISO, shutter speeds and white balance in order to get the best possible shot for the database.

Figure 2: Caption: A standard record shot. Rim and body sherds of a burnished Colonoware vessel with scale, object 2669. Karen E. Price, Mount Vernon Archaeology.

I have now expanded my role from photography intern to Preservation Photographer. There are generally two types of photographs that I take both in the field and in the studio: record shots (figure 2) and creative or candid shots (figure 3). These are not mutually exclusive and all follow the same basic compositional guidelines. I always photograph in RAW format (as opposed to, say, JPG), constantly assess the light, and ask myself if the picture makes sense to the viewer.

Figure 3: A candid, creative shot. Volunteers hold lithics excavated from the Slave Cemetery Survey. Karen E. Price, Mount Vernon Archaeology.

At work my general tasks are to document our current excavations and pre/post/ongoing restoration projects around the Mount Vernon Estate. I also do a bit of landscape photography to aid in the preservation of Mount Vernon’s Viewshed looking east across the Potomac River and I’m starting to assist our Collections staff with in-house photography. My favorite, however, is artifact photography, which is where I feel most comfortable creatively. This not only involves standard record photographs, but dramatic detail shots (figure 4), 360 degree spinning GIFs, and thematic pictures (figure 5). I love how sometimes, with just the right lighting and depth of field, a picture can bring out qualities in an artifact that aren’t as visible with the naked eye (figure 6).

Figure 4: A detail shot. By using raking light coming in from only the left side I was able to bring out the C and sunburst design on this tobacco pipe heel. Object 2906. Karen E. Price, Mount Vernon Archaeology.

I’ve got a couple of projects (experiments) lined up for 2015 that will take me out of my comfort zone and hopefully enhance my photographic skills. For starters, a new photographic technique called Reflectance Transformation Imaging (RTI) that synthesizes multiple photos of an object, each using a different angle of lighting, to bring out 3D details in a 2D format. I’m also going to try and create actual 3D files through digital images using Agisoft Photoscan.

Figure 5: A thematic shot. Buttons excavated from the South Grove Midden. Karen E. Price, Mount Vernon Archaeology.

My main goal in this job, however, is to create a standard protocol for field and artifact photography that anyone can follow. This ensures that archaeologists do not have to simply “point-and-shoot”, but can follow guidelines for setting up a shot. And really, taking a second to think about the composition of a shot will do wonders for the quality of our photographs. In the studio these include photographing in RAW format so that you can correctly adjust gray balance, orienting the object correctly (figure 7) and blocking reflective glare from ceramics. Forget RTI and 3D imaging- basic, high-quality archaeological photography can be done in-house, on a fairly low budget, and by non-photographers.

Figure 6: An hua on porcelain can be difficult to see. By limiting the amount of light the porcelain received I was able to bring out the design a bit more. Chinese Export Porcelain plate, object 2645. Karen E. Price, Mount Vernon Archaeology.

There are a few things you may want to invest in if you’d like to up your photographic game. I’m a big proponent of photographing in RAW format so you’ll need a digital camera capable of this, which will be your biggest investment. You’ll also need a computer software capable of opening RAW files (I use Adobe Photoshop but RawTherapee is a budget-friendly option). In the studio I recommend having an X-rite color checker (this will help correctly color balance your photo), two photographic strobe lights, a tripod, small scales, and a suitable background for your artifacts (black velvet works well with most objects). If I had to pick the bare necessities? The camera, the software, and a color checker.

Figure 7: It can be difficult to arrange multiple non-mending sherds for a photograph. I do my best to line up the decoration and mimic the original curvature of the artifact. Delftware plate, object 2589. Karen E. Price, Mount Vernon Archaeology.

I think that with the current technology we can, and should, expect a change in the discipline in regard to how it treats photographic documentation. I’m all for a great iPhone photo, but I’d love to see archaeologists taking the camera off automatic and experimenting with what today’s digital cameras can do. Our pictures may not speak a thousand words, maybe only a handful. But, if they open up dialog about archaeological research and material culture, or even just get the general public excited about our discipline, then I think they’re worth the effort.

I’d love to hear your tips, thoughts, or questions on archaeological photography!

You can see some of Karen’s preservation photographs on the Mount Vernon Midden database, the Digital Archive of Comparative Slavery, COVA’s Culture Embossed, on Facebook, and on the cover of American Archaeology, fall 2013, volume 17, number 3.

Check out the other #TechWeek Posts:

Tech Week: Photography in Archaeology by Jonathan Libbon
Going Interactive Underwater by Drew Fulton
Photographs into Models: Documenting the World Trade Center Ship by Carrie Fulton

Photographs into Models: Documenting the World Trade Center Ship

By Carrie Fulton

If you attend any archaeology conference or glance through recent issues of journals, you will quickly see the extent to which photogrammetric documentation has become a part of an archaeologist’s toolkit. Take a few photos, import them to software, and hit go. Violà! You now have digital models of your site or object. Ok, so the steps are slightly more detailed, but with new technology, the interfaces and steps to producing accurate models are getting easier and less technical.

The benefits of digital recording are massive: increased speed of recording, preservation of three-dimensional information, geo-referenced data, digital preservation of contexts that are destroyed through the process of excavation, and easy dissemination of information. How can this technology be used effectively? And are there drawbacks? If so, how can they be mitigated?

Let’s look at the excavation and documentation of the remains of a late 18th-century ship discovered during the construction at the World Trade Center site in July 2010.

Figure 1: Remains of the World Trade Center Ship looking from the stern towards the retention wall. (Photo: K. Galligan)

Since the ship was found in one section of an active construction site, we had to move quickly so the timbers could be removed and construction could continue. Approximately 32 feet of the ship’s stern (back end) remained. However, a modern retention wall bisected the ship and destroyed evidence for much of the forward half of the ship except for a very small section of the bow (forward end) of the ship that was uncovered in August 2011 when the other side of the wall was cleared.

To capture the relationship between timbers we used laser scanning, photographs, videography, and sketches. This enabled us to give each timber a unique identification so that upon disassembly we could keep track of each piece and reconstruct the in situ relationship. Once removed from the site, we had more time to analyze the timbers, but the next step in the preservation of the ship hadn’t been determined. We were faced with the question: How do we record each timber accurately and quickly? We settled on an approach that combined traditional methods for documenting timbers with recent advances in photogrammetry to create three-dimensional digital recordings of the timbers.

Figure 2: Making a 1:1 tracing of a frame. (Photo: D. Fulton)

Traditionally, nautical archaeologists record the dimensions by tracing the timbers in 1:1 reproductions or making scaled drawings of each face (Figure 2). The advantage of this approach is the close examination and documentation of each face, noting patterns in fasteners, tool patterns, and any biological growth that might be indicative of post-depositional processes. However, this method is extremely time consuming, and there is the possibility for dimensions to be distorted in tracing (due to parallax) or in condensing information into a scaled drawing.

For the best use of resources and time, we made 1:1 tracings of the two sides of the frames where the ceiling planking and the outer planking were attached. This allowed us to record the arrangement in nail patterns, which is crucial to answering questions about whether the ship timbers had been repaired. To document the curves of the frames that are difficult to render in two dimensions, we used photogrammetry to generate three-dimensional models. For all other timbers of the ship, we also used photogrammetry rather than tracings.

Each timber still had its own data sheet with notations for tool marks, measurements, marine growth, and any other information that might aid in the reconstruction of the ship and its life history. However, the timber is now preserved in a digital record as a three-dimensional model. Creating a model involved a three-step procedure:

Figure 3: Drew Fulton photographs a frame which was imported into PhotoModeler Scanner.

STEP 1: Photograph the timber. For the version of PhotoModeler Scanner in 2010, stereo pairs of photographs were taken from each side of the object, with the photographer maintaining a 45-degree angle between the object and the camera. To aid in linking the photographs together, computer generated and coded dots were placed around the timber. We used push-pins to mark nails and other features so that they could be easily spotted in photographs. This allowed us to maintain the high degree of detail afforded by the tracing method while decreasing recording time.

Figure 4: 3D model of a timber created in PhotoModeler Scanner.

STEP 2: Generate 3D data. The photographs were then used to create a 3D model in PhotoModeler Scanner by first creating cloud data of the timber and then transforming the cloud data into a triangulated mesh. This mesh recorded the curves of the timbers and was exported into the NURBS modeling software Rhinoceros.

Figure 5: Reconstruction of the small deck.

STEP 3: Render into a model. Using Rhinoceros, a 3D image was created and nails were added following the locations of preserved nails. From this model, individual drawings can be produced to link the timber to information from field notes and examination in the lab. Additionally, these individual pieces were combined digitally in Rhinoceros to reconstruct the ship, using the aid of data from the laser scan.

Figure 6: Reconstruction of a frame in Rhinoceros.

The emphasis for us was integrating three-dimensional recording techniques with traditional measuring and documentation techniques to quickly and accurately record the ship and enable analysis when access to the actual timbers may not be possible. On the one hand, it is easy to see the benefits: it’s a fast process in the field, it preserves and records curves very well, it facilitates collaboration and dissemination of information with digital files that can be easily shared. On the other hand, we tend not to think about the costs associated with it: digital cameras with high resolution files requiring terabytes of storage, the possibility of having corrupt hard drives, and long hours and tedious manual work to render the digital data into final forms. Most significantly, while advances in digital technology enable better documentation, will these advances make our early attempts obsolete? For example, the version of PhotoModeler Scanner that we used has already been updated, no longer requiring stereo-photographs. Using the photographs from the World Trade Center Ship, I am eager to try rendering models using newer versions of software to see what these changes might mean for our data. However, what would happen if I could no longer open the software used to access the data?

The power of photogrammetric techniques lies in their integration with traditional techniques, using them alongside measurements and drawings to record the archaeological data. While it’s a helpful tool, we still need to future-proof our data. From the 3D models, we can still produce standard drawings and take measurements. By supplementing recordings in the field and tape measurements, this redundancy can help catch errors in recording while producing a complete visual record of the object.

While moving forward with new technologies and digital recording procedures, are we at risk of advancing too quickly? Is there a risk that we will no longer have the computer programs or software to open these files and thus render our documentation obsolete? Or, is this a way of ‘future-proofing’ our data?

ACKNOWLEDGEMENTS

Archaeologists at AKRF, INC., Diane Dallal, Michael Pappalardo, Elizabeth Meade, and Molly McDonald, managed the excavation of the site for the Lower Manhattan Development Corporation (LMDC). The principle investigation of the ship was led by Warren Riess (University of Maine) and Carrie Fulton (Cornell University). Drawings were made by Kathleen Galligan. Drew Fulton (Drew Fulton Photography) photographed onsite panoramas and the timbers for photogrammetry. Timbers were initially stored at the Maryland Archaeological Conservation Laboratory and are now held in the Conservation Research Laboratory at Texas A&M University. The LMDC and the Port Authority of New York & New Jersey provided funding for this project.

Check out the other #TechWeek Posts:

Tech Week: Photography in Archaeology by Jonathan Libbon
Going Interactive Underwater by Drew Fulton
Preservation Photography: Roles and Rules by Karen Price

What the Tech…?!

A recent SHA Academic and Professional Training Student Sub-committee survey asked student members what technologies are necessary in archaeology and as professionals. In continuing support of the identification, discussion, and application of relevant technologies, student member, Tim Goddard, agreed to (re)introduce the concept behind the Technology Room – a great space for students and professionals to engage in one-on-one conversations about current technologies in historical archaeology.

Thank you for the opportunity to blog about the Technology room from/for a student’s perspective. I gladly serve on the SHA’s Technology committee. I am also a Graduate student finalizing my PhD. Several years ago, when I first joined the committee, one of my first conversations with fellow members explored the challenges of presenting the use of technology to SHA members who were not already a part of the “technology crowd”. For many previous years, the same group of colleagues presented the latest technologies they were playing with and composed the small number of technology sessions at annual meetings. Despite the fun of this, rarely did we see new faces – especially people wanting to learn about technology.

The Technology Committee was created to serve the SHA’s needs as they relate to technology. This can include almost anything, which has been the case thus far. Only the Website has remained outside the purview of the technology committee. We serve to advise the SHA board and any interested members on almost any technology-related application, either for the Society, or for use in the field of archaeology. As you can imagine, this is an extensive scope. The diverse technical needs of archaeologists require that the committee have a number of members from a wide variety of technological backgrounds. We cover topics including: social media, geophysics, remote sensing, data collection, data management, GIS, LIDAR, 3D, virtual worlds, network management, etc.

pXRF Technology Leicester 2013. PxRF technology allows us to identify the chemical composition of soils and/or artifacts. The committee regularly offers workshops at the SHA to learn how to use this technology. The following link is an example of one use by one of our committee members David Morgan (http://ncptt.nps.gov/blog/pxrf-presentation-at-lasmaa/).

With some of my own work in WebGIS, I was frustrated that it was not possible to demonstrate my research in a virtual poster session allowing people to view and interact with my presentation via a computer terminal. To do so would have meant me renting a table space, electricity and Wi-Fi, in the exhibition room. Something that is not really feasible for most students! I also know firsthand from teaching that there are a large number of archaeologists that have technology phobias. This fear can be found in young students as well as established emeritus colleagues around the world. So I wanted to know how we could better serve those members at the conferences. We developed the idea of the Technology Room.

Our first experiment with a dedicated technology demonstration space was at the 2011 meeting in Austin, Texas. We decided to focus on three to four key technologies that we felt every archaeologist should know about. We found a handful of our colleagues working with these technologies and invited them to bring the actual technology to our room and to sit down for a block of time to answer questions and provide demonstrations, and hands on experience were possible, for interested colleagues. We strove to recruit archaeologists using technologies in their research projects rather than sales representatives. The idea was great and we got positive feedback, but our execution that first year needed some help.

LIDAR technology Leicester 2013. LIDAR typically comes in aerial or terrestrial applications. This is a terrestrial style scanner being demonstrated in the Technology Room. A good link to see LIDAR uses in heritage is http://archive.cyark.org/?gclid=CPX7m8a13boCFQLl7AodR0oAXw.

In the following years we continued to showcase various technologies by having practicing archaeologists demonstrate the technology in the exhibition room, which was always problematic and also made communicating difficult with all the noise. Last year, in Leicester, was the first year that we had our own dedicated room, making communicating much easier. We saw a drop in traffic indicating that we still need to get the word out there about the Technology Room. An undergraduate student who I supported at Leicester found the Room worth noting in a blog he posted about his first conference experience. There is something for everyone in the Technology Room.

UAV Technology Leicester 2013. Unmanned Aerial Vehicles are popping up everywhere in archaeology. From a simpler Quadcopter to multiple thousand dollar units with multiple sensor platforms are finding many uses every year in archaeology.

What are the purposes of the Technology Room?

  1. Present the latest and greatest technologies being used in archaeology.
  2. Have a practicing archaeologist familiar with the technology to educate others about what did and didn’t work.
  3. Learn what pitfalls to avoid.
  4. The real costs involved.
  5. Share technology driven research that can’t always be demonstrated in a traditional symposium.
  6. Network with various technology minded colleagues

What is the benefit to Students? Students:

  1. learn about technologies that you might not know about through your own institution;
  2. are often our best presenters as they grew up in a technology age and can help others with technology phobias in a professional context;
  3. can learn and see technology in a low pressure environment;
  4. and can network to find projects using a technology they might be interested in working with.

So I challenge you:

What Technology are you interested in? What role do you feel technology should play in archaeology? What are the problems we face with technology? How can we (SHA) or your institution better train you for technology-related applications?

Comment below as well as stop by the Technology Room this January.

Tim Goddard