Fogbow on a Misty Night

March 24, 2016


Photographer: Arnaud Thiry
Summary Authors: Arnaud Thiry; Jim Foster

Shown above is a view of a fogbow observed near Sarraltroff, France. I was taking a walk on a very misty night and noticed that when I passed under street lamps a faint arch of light stood before me, directly opposite the source of illumination. Because of its near-circular shape, angular size and position, I concluded that it was a kind of rainbow, stemming from the very dense fog and the streetlights. Fogbows or cloud bows result when light interacts with minute fog droplets. Because the droplets are so tiny, unlike the much larger raindrops that cause a rainbow (more than ten times as big as fog droplets), the fogbow is very dim and nearly colorless compared to its more illustrious cousin. Notice that this bow has no obvious color gradient. The photo was taken on February 6, 2016.

Photo Details: Camera Model: Canon EOS 5D Mark III; Lens: EF16-35mm f/2.8L II USM; Focal Length: 16mm; Aperture: ƒ/2.8; Exposure Time: 5.000 s; ISO equiv: 100. The photo was edited using Adobe Photoshop Lightroom 6.0 (Windows) — for wide-angle perspective correction, chromatic noise reduction, etc.