Parhelion Above Arc de Triomphe

September 16, 2012

ArcdeTriomphIMG_7572b (4)

: Bertrand Kulik; Bertrand’s Web site
Summary Authors: Bertrand Kulik; Jim Foster

French arc 2The photo above showing a gorgeous parhelion or sundog above the Arc de Triomphe in Paris, France was captured just before sunset (7:55) on August 31, 2012. Motorists snarled in traffic were treated to two impressive “arcs” this late summer’s evening. Sundogs result when sunlight refracts through oriented, hexagonal plate ice crystals found in cirrus clouds. They’re observed at the same altitude as the Sun and when seen late in the day or early in the morning, as was the case here, they’re found 22 degrees away from the Sun. Note that the Sun is just off the left side of the picture. Larger diameter ice crystals produce the most colorful arcs.

Photo details: Camera Maker: Canon; Camera Model: Canon EOS 7D; Lens: EF100-400mm f/4.5-5.6L IS USM; Focal Length: 105.0mm; Aperture: f/9.0; Exposure Time: 0.0013 s (1/800); ISO equiv: 100; Exposure Bias: none; Exposure Mode: Manual; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Digital Photo Professional.