As I readied myself and my camera for a dive in Yellowstone Lake, the largest body of water in Wyoming’s Yellowstone National Park, I thought I was on top of my game. I had recently specialized in underwater photography at the Rochester Institute of Technology, and had most photographic techniques figured out. I knew enough to wear several layers of thermals under my drysuit to withstand frigid water temperatures of 38° F. Yet I was in for a surprise. When my boss told me that we would be using a photographic technique called photogrammetry, I was taken aback, as it was entirely new to me. Little did I know, it was a groundbreaking new technology that would change how I looked at photography.
This was my first trip as an intern with the Submerged Resources Center (SRC), a National Park Service (NPS) program that uses marine archaeological expertise and media technology to document underwater features in the National Park System. SRC and the Our World-Underwater Scholarship Society sponsored my adventures last year exploring coral reefs, kelp forests, shipwrecks and other underwater wonders with dive teams in the parks.
Our photographic subjects during these dives at Yellowstone were several rowboats that had been sunk in front of Lake Hotel in the early 20th century. Brett Seymour, my boss and the chief photographer at the SRC, told me that photogrammetry is a photographic technique that captures a subject from all angles. These angles are then stitched together using software from Autodesk called Recap 360 to produce a 3-D model. By working in a circular pattern and taking a photo every few inches around the subject, you can create enough overlap for the software algorithm to put together a seamless model with thousands of data points.
Photogrammetry has a multitude of uses, including producing virtual 3-D models for educational purposes, animation, and even 3-D printing. But what I quickly learned from observing Brett was that producing 3-D models underwater was anything but easy. The photographic pattern is relatively simple on land; underwater it requires a mastery of buoyancy to control your depth within the inch—not to mention complete control over your lighting and exposure underwater. It was hard, to say the least, but I managed.
Later, on my own, I used photogrammetry in Valor of the Pacific National Monument in Oahu, Hawaii. The site of the attack on Pearl Harbor was a significant place to employ my new expertise. Armed with advice from Brett, I focused on a small but historically significant feature on the USS Utah: a hatch that leads to an underwater tomb, where survivors of the attack on Pearl Harbor can choose to be buried once they pass on. Determined to honor the Americans who lost their lives in the attack, I made sure to maintain a steady photographic pattern to capture each angle of the hatch, including the large chain that lies across its front. It was hard to control my buoyancy and avoid stirring up silt by kicking my fins too hard, but I pulled it off. Around 230 photos and several hours of processing later, I had my first successful 3-D model.
The model joins several others in the park’s database that chronicle gradual damage to important features, and are shared with park visitors for educational and interpretive purposes. The underwater application of 3-D modeling brings cultural features to the surface for everyone to appreciate.
With pride in my photographic success, I decided to explore the applications of 3-D modeling with other photographic subjects. In Kalaupapa National Historic Park on Moloka’i, Hawai’i, I teamed up with Sly Lee, the biological science technician in the park. Sly’s experience with photogrammetry mainly focuses on producing 3-D models of corals for scientific analysis. Documenting the intricate structures in each coral specimen demands intense focus and attention to detail, but produces aesthetically beautiful results and a potentially valuable scientific tool.
My experiences diving in and photographing the National Parks revealed both the potential of this technology and the beauty and historic legacy of our underwater resources. This new photographic technique presents a steep learning curve for photographers, but the 3-D models it makes of underwater wonders will capture the public’s imagination. The technology is still developing, but with a multitude of possible educational and scientific applications, it won’t be long until we’re taking virtual tours of shipwrecks and coral reefs all over the world.