Yosemite Falls Moonbow

Posted by Don Smith (California, United States) on 24 April 2008 in Landscape & Rural.

A lunar rainbow is a rare sight. If one's eyes are sensitive enough to the night sky, one may spot a faint outline of the bow, usually in black-and-white. However, last Friday evening, a steady wind was blowing the mist at the base of Yosemite Falls, and a 99% full moon rose in a direct line with the lower falls. Thanks to the lack of reciprocity failure in digital capture, a 6-second exposure at ISO 1600 at f2.8 allowed for the lunar rainbow to appear! The hardest part of capturing this image was dealing with other photographers and sightseers! Once I secured a spot to place my tripod, I had to try my best to keep my lens clean of the blowing mist. A frustrating experience led to a marvelous capture! To see more of my work, purchase a copy of my book On the Edge, or to learn more about my workshops, please visit my website at http://www.donsmithphotography.com.

Comments (5)

DarkElf from Perth, Australia

outstanding photo, the rainbow has come out beautifully, i really like the overall mood of the photo and the bluish moonly tones, certainly something different!

25 Apr 2008 8:30am

Don Smith from Hollister, United States

Thanks Dark Elf. Lower Yosemite Falls fortunately lines up directly with the moonrise. The best months are April and May. This year's heavy snowmelt contributed to the success of this image by creating an explosion of mist allowing for defraction. A steady breeze also helped stir the mist. Keeping the moon (just as with the sun for a rainbow) over your shoulder is a must. The height of the moon and the photographer's position must form an intersectig angle of 42 degrees in order to see the moonbow (or a rainbow in the daytime). It's interesting that no two people see the same moonbow/rainbow. Also, one can get the moonbow/rainbow to move laterally as long as the moon/sun stays over your shoulder (just look down your shadow line). I could actually make out the bow in black-and-white, and at one point could see some faint color. The cones in our eyes - which transmit color information to the brain - shut down at varying low-light illumination levels for different people. This is why some have a greater sensitivity to seeing color at night. When our cones can no longer transmit color signals, our rods (of which we have millions per eye) take over and transmit black-and-white signals. Fortunately, digital camera have no such problem. I actually had people lined up behind me wanting to look at my LCD. They couldn't believe what I had recorded!

25 Apr 2008 2:56pm

Barbara from Florida, United States

Outstanding capture! Interesting story on how it became a magnificent photo.

27 Apr 2008 1:52am

Don Smith from Hollister, United States

Thanks Barbara. Moonbows are really fun to capture because one really can't see them with the naked eye! It's kind of like that old darkroom magic except you get your results immediately with the LCD!

29 Apr 2008 1:59pm