Pine Needles, Sunlight and Concentric Circles

November 21, 2018

PinePillar_DSC2096gs (1)

Photographer: Gaurav Shah
Summary Authors: Gaurav Shah; Jim Foster

If you're a keen-eyed observer you may have noticed concentric circles when the Sun or headlights shine through windshields scratched by wiper blades, through shrubs having shed their leaves or even through pine needles, as shown above. What causes these circles? The needles themselves are oriented randomly. However, the ones that scatter light back to the camera happen to be oriented tangentially to the circle between themselves and the Sun, resulting in the appearance of a series of concentric circles. Photo taken on October 14, 2018, at 4:44 p.m.

Photo Details: Camera: SONY ILCE-6500; Software: GIMP 2.8.16; Exposure Time: 0.0080s (1/125); Aperture: ƒ/8.0; ISO equivalent: 800; Focal Length (35mm): 150.