This photograph was taken in the spring north of Grand Rapids, Manitoba. A friend and I were walking through a burned-over area looking for limestone caves, and had picked a day when the weather had turned cold, so as to be able to spot undiscovered openings from the plume of moist air emanating from their mouths. The day was turning warmer, and the air was totally still, resulting in the air being filled with a fog of extremely fine, relatively motionless ice particles. As we walked, struck by the absolute silence all about us, we suddenly became aware of the formation of the dramatic refraction pattern shown. A crescent similar to the one touching the top of the annulus around the sun was observed on the bottom of the annulus. At the peak of the effect, the horizontal line passing through the sun was visible over a complete 360 degrees. The effect lasted for about an hour, until a slight breeze came up.