October 06, 2004
Rainbows can often be seen in the spray from a waterfall or a garden hose. Outside the primary rainbow, a secondary bow is sometimes visible, as it is in this photo of the appropriately named Rainbow Falls, which is located in Devils Postpile National Monument, California. The colors of the secondary bow are fainter and in reverse order because the rays of sunlight are relected twice inside each droplet, versus just once for the primary bow.
Although a rainbow formed in spray seems closer than a conventional rainbow, they're both virtual images formed at infinity. This can be frustrating for a photographer who dosn't have a wide-angle lens, since "backing up to fit it all in" doesn't work -- the bow remains the same angular size no matter how far away from the spray you are!