The Art & Science of Camouflage
By: Elise Hugus, May 18, 2012
Daniel Cojanu/TEDx Woods Hole - Dr. Roger Hanlon, an MBL senior scientist, demonstrates the amazing camouflage skills of octopus, squid, and cuttlefish, and how art is informing science.
You see camouflage in fashion, on military hardware and in nature. But what exactly does it take for fashion designers, engineers or Mother Nature to match 3-D objects with their surroundings?
That is exactly what Roger Hanlon, a senior scientist at the Marine Biological Laboratory in Woods Hole, is trying to find out.
The marine biologist is taking an innovative approach to studying the behavior of cephalopods—a class of mollusks that include squid, octopus and the incredibly inconspicuous cuttlefish.
In collaboration with visual perception experts, architects, engineers and illustrators and animators, Dr. Hanlon is trying to figure out how these marine creatures blend so well into their environment—and what we can learn from them in order to design products that do the same.
“No one has ever tried to quantify camouflage. As we began to study it, we realized we need to quantify it, but we don’t know how to do it,” Dr. Hanlon said while taking time for a chat in his Woods Hole office.
“That’s turned me onto art, and how an artist’s approach differs from biology.”
An ‘aha!’ moment
While animal camouflage has been evolving for thousands of years, the British Army first developed it for military purposes during the Napoleonic wars. Other European armies soon adopted uniforms to blend better into their surroundings. In fact, the term “camouflage” was borrowed from the French word “camofleurs,” the painters and set designers who built observation trees and other natural-looking disguises on the battlefields of World War I.
Dr. Hanlon has been interested in cephalopods since an encounter with an octopus in 1968, but it wasn't until a 1997 diving trip in the Cayman Islands that he had his first “aha!” moment about camouflage.
He had been shallow-water diving for hours, attempting to capture an octopus changing color on camera. He had no success until he accidentally snuck up on what he thought was a seaweed-covered rock.
To his astonishment, the “rock” suddenly transformed into an eight-armed sea creature that swam away, leaving a trail of ink behind it.
Ever since that day, Dr. Hanlon has been studying this video. “I learned a lot from that image. We’re still trying to understand it mathematically,” he said.
A trick of the eyes
Leafing through a coffee table book by camouflage artist Bev Doolittle, Dr. Hanlon said he has continued to find patterns and blending techniques everywhere in the art world, from the Impressionists to the photography of Ansel Adams.
And that has been his second, albeit more drawn-out “aha” moment. Working with artists, Dr. Hanlon said, has allowed him to understand human perception and discover new applications for his research.
“Whether it’s an animal or a print or material batch, it either blends in or stands out. I want to find out how or what makes it stand out,” he said.
But it is easier said than done. In a 2009 workshop he held with a cross-disciplinary group of artists, scientists and engineers, Dr. Hanlon found that the group had a hard time communicating their diverse approaches to one another.
“Speaking to engineers, one of my least favorite words is “texture.” It means something entirely different to a visual perception expert versus a builder,” Dr. Hanlon said.
On the other hand, he added, “engineers need numbers to reproduce things. Artists go through the same process, but without numbers.”
After reviewing thousands of high-resolution microscope images of cuttlefish skin, the working group was able to articulate some key elements of how camouflage works: color, contrast, and pattern, as well as something called “edge design.”
Dr. Hanlon’s team discovered a “Mount Fuji” effect in the skin, in which small bumps would develop in response to its perception of its surroundings, similar to how goose bumps develop on human skin in the cold.
The peaks of these mini Mount Fujis were light, while the valleys were dark, forming a pattern that makes the animal appear to have the same texture as its background.
“It created these false edges where the real figure was obscured. We figured out from the animal how to defeat edge recognition, by playing tricks on the eyes,” Dr. Hanlon said.
Bridging the gap
Using the microscope stills as a guide, animator Basia Goszczynska has been working with members of Dr. Hanlon’s team to develop a video showing just how a squid’s muscles contract to create the camouflage effect.
“Artists can serve as a bridge for getting science out to the world,” said Goszczynska, who worked in theater set design and the film industry before joining Dr. Hanlon’s lab earlier this year.
“A lot of people believe that art and science are completely different, that one is subjective, one is objective. Roger [Dr. Hanlon] comes up with these complicated results that I simplify through animation and design,” she said.
Working with Goszczynska helps Dr. Hanlon explain the cephalopods’ highly developed camouflage process to engineers who are interested in its applications—for everything from light-sensitive computer and mobile phone screens to energy-efficient architecture.
Discovering the mechanics of camouflage also opened up new questions for Dr. Hanlon. For one thing, cephalopods are colorblind, raising the question of how they are able to match the color and texture of a rock or seaweed so precisely. Further, he wondered how cephalopod predators—a porpoise, for example—perceive this colorful shape-shifting.
As astonishing as his underwater video is, humans only are seeing a small part of the available light spectrum, Dr. Hanlon points out.
To overcome the limits of human perception, Dr. Hanlon is taking advantage of a National Science Foundation grant to get a custom-built Hyper Spectral Imaging camera equipped with 700 megapixels. For comparison, your iPhone probably has 8 megapixels.
With the aid of the HSI camera, Dr. Hanlon and his colleagues will finally be able to see what a cuttlefish and its predators see, unlocking yet another mystery of evolution.