Streaky Rainbow in Zion National Park

July 28, 2017

Photographer: John Adam
Summary Author: John Adam 

July 2017 Viewer's ChoiceThe photo above shows a colorful but streaky band of light at a rock outcrop taken along the Emerald Pools Trail, Zion National Park, Utah. It was a beautiful sunny day, with no rain, but isolated showers of water (from an earlier rainfall) were seeping through and over the rock edges. By positioning myself just right, I was able to capture the rainbow (after all, it was caused by falling drops of water) with a fairly slow shutter speed to reveal the history of each drop as it generated the spectrum of colors. This was a primary bow -- note the red color at the top of the bow. In a primary bow the light is refracted twice at the surface of each drop and reflected once from the back surface. My position and the rock configuration were such that I couldn't see any hint of a secondary bow (formed by an additional reflection inside the drops). But this unexpected bow made for a refreshing break on the way up the canyon. Photo taken on May 12, 2017.

Photo Details: Olympic SP 100EE camera; 17 mm; f/13; 1/60 sec. exposure, ISO 500.