December 19, 2014
Summary Authors: P.Nikolakakos; Jim Foster
The misty arc shown above was photographed over a recently plowed field near Sparta, Greece. Other than patches of rather dense fog, the weather was fair this fall morning. Full sunshine behind the camera illuminated the scene. This is a cloudbow or fogbow. Sunlight interacting with fog droplets rather than raindrops forms this bow. The tiny droplets act to diffract sunlight rather than refract it as would occur in raindrops. Wave interference leading to overlapping wavelengths of visible light results in the washed out colors. Typically, the bigger the droplet/drop size the more pure the color. Because little color can be detected in this pearly bow, the droplets are likely less than about 0.1 mm in diameter. Photo taken on October 12, 2014.
Photo details: Camera Model: Canon EOS 6D; Lens: EF24-105mm f/4L IS USM; Focal Length: 24mm; Focus Distance: Infinite; Aperture: f/13.0; Exposure Time: 0.0016 s (1/640); ISO equiv: 125.