FAIRBANKS - Kenelm Philip says it’s taken him 27 years to figure out how to successfully photograph the eye-catching color of the Solar Borealis Arch that spans the exit drive from Fairbanks International Airport onto Airport Way. His previous attempts to capture the prism-radiating colors on film or with digital cameras produced only white images.
So a couple weeks ago, the retired University of Alaska Fairbanks scientist decided to take a closer look at the metal sculpture that, depending on the angle of the sun, provides a light show similar to a prism or rainbow for people passing beneath.
On closer inspection, what Philip found was a smooth layer of clear plastic covered in quarter-inch squares, with each small square cross-hatched diagonally to form four tiny triangles covering the metal surfaces of the white arch.
“The top and bottom triangles have numerous small horizontal lines that will split the colors of the sunlight up and down, and the side triangles have lines that go up and down and they split the sun sideways,” Philip said, which explains the difference in the color placement in his accompanying photograph.
“If you look from the sun to the arch and the arch to your eye there will be an angle between those lines and the horizontal component will change the color you see sideways,” he said. “And as the vertical angle changes, the colors change vertically. What you are seeing is the combination of all of those.”
The arch viewed from a distance produces only one color, but by drawing closer at an angle, different colors will emerge from top to bottom, Philip added.
“I realized that the diffracted sunlight coming off the arch is very, very bright and the background predominates; and the arch comes out white because it is overexposed,” he said.
Philip’s research field trip provided the “secret” to catching the archway’s color with a camera. And he is happy to share.
“Deliberately set the camera to -2 EV — that is two F-stops down and it produces an underexposed image,” Philip said.
“You now get the (arch) colors to show, but the background will be very dark,” he said.
Then go to Photoshop Elements, Philip advises, to bring up the background without changing the colors of the arch at all.
Although Philip earned a doctorate in astronomy, a few years after coming to Alaska his scientific interests reverted to his childhood love of butterflies. He has been collecting and photographing butterflies and moths all over the state in the first ever Alaska Lepidoptera Survey, since 1970, and has amassed the second-largest collection of North American arctic butterflies in the world.
In his retirement, Philip is a senior research scientist at the UAF Institute of Arctic Biology, a research associate at the University of Alaska Museum of the North as well as the National Museum of Natural History at the Smithsonian in Washington, D.C.
Contact staff writer Mary Beth Smetzer at 459-7546.