Mark Thorpe, a Japan-based wildlife photographer, has made a timelapse of an event that is only fully visible twice a year: The passage of the Milky Way over Mount Fuji.
"I found out that while you can see the Milky Way during May and June, it's only on the new moons—when there is zero moon cover—that you can see it very clearly," Thorpe told me over the telephone. "This means that there are only about six days of the year when you can get perfect conditions to shoot this."
Outside of these months, the Milky Way is too low in the sky to capture perfectly on camera.
Thorpe, an Emmy Award-winning wildlife cameraman with 20 years of experience, moved to Japan two years ago with his Japanese wife and their son. He combined his recent interests in timelapses and astrophotography to come up with the shot.
Thorpe started photographing at 9 PM using a Canon EOS 5D3 camera, and captured additional shots with a GoPro and iPhone.
He set up his camera to shoot a 25-second exposure with a 30-second interval. That meant, said Thorpe, that the camera only had five seconds to write an image and rest before taking the next one. He repeated the process 698 times for six hours to end up with a 25-second timelapse showing the passage of the Milky Way over Mount Fuji.
Thorpe said that the Milky Way was barely visible to the naked eye, and that in order to capture it, he left the aperture of his camera lens wide open, with a super-sensitive ISO setting of 3200. These settings, along with the slow shutter speed, let a lot of light into the camera.
"I couldn't have any artificial light source on the image as otherwise I'd get too much ambient light pollution. You can see the glow in the background; that's the fluorescent glow from Tokyo in the night sky," said Thorpe. He said he sneaked onto military ground so his camera would pick up less of this visual noise.
"It's an iconic scene as you've got the view of Mount Fuji and something (the Milky Way) that passes over it so seldomly in the course of a year," he added.
Cool Japan is a column about the quirky and serious happenings in the Japanese scientific, technological and cultural realms. It covers the unknown, the mainstream, and the otherwise interesting developments in Japan.