"A giant wave cloud was over Bozeman, MT and I knew it would produce some awesome atmospheric optics phenomena, so I grabbed my camera. When I looked up, I was rewarded with the most beautiful corona and iridescence I had ever seen. I used a light pole to block the sun. I have included three images, but I have many more of equal beauty.
Light diffracted by individual miniscule water drops is the source of the corona and iridescent colours. Drops of nearly equal size make the best ones. Wave clouds with their fast forming and equally fast evaporating droplets provide ideal conditions.
The wave cloud was moving from the right of the images to the left...very quickly I might add. So quickly that none of the photographs I took really resembled one another. As each part of the cloud kept moving in front of the sun, a different corona would form. It was the most amazing thing I've ever seen. I was taken aback by Nature once again."