Scattered Light

Gilomen Road near Marine, Illinois
Photograph by Tom Atwood

This photo is deceiving. It looks like it was taken at dawn or dusk, as if the glow at the horizon is caused by the sun. But the shot, an 8 minute time exposure, was actually taken near midnight (on a very cold night). The sky is blue partly because of the long exposure, but mainly because there was so much scattered light in the area. The light is concentrated near the horizon--street lights, farm lights, billboards, cars, etc. This ambient light, what some call "light pollution," gives the horizon its dawn-like glow. It also has caused a magnificent, natural sight that people have enjoyed for thousands of years to vanish: the starry night. Shutter: 8 minutes; Aperture: f/5; ISO: 200; Focal length: 18 mm.