How to find moonbows in Yosemite

Blog post:
Chasing Moonbows in Yosemite Valley at Night
http://activesole.blogspot.com/2008/05/chasing-moonbow-in-yosemite-valley-at.html

Trying out the new Collections feature…

Originally shared by +Jeff Sullivan

I should explain a bit more about how you can find the Yosemite night "moonbow" conditions depicted in this image I referenced yesterday. Since rainbows occur with consistent and predictable geometry, astronomer Don Olson of the University of Texas is able to predict the days and times when the full moon will be in the right place to create night rainbows (lunar rainbows, "moonbows") in the mist of Upper and Lower Yosemite Falls: http://uweb.txstate.edu/~do01/

For a few more examples of Yosemite moonbow photos, here are the posts on my blog from moonbow photo shoots I pursued in 2008 and 2009: http://activesole.blogspot.com/search?q=moonbow My shooting and post-processing tools have come a long way since then, but at least you can see some of the angles and compositions available if you run around the Valley on a moonbow night.
I've used this image to start a Night Photos album, which I'll add to as time permits and as I capture new shots. These first 7 shots in the album were all taken with my Canon 5D mark II using the EF 16-35mm f/2.8 lens (at 6400 ISO for dark sky Milky Way shots, as low as ISO 800 for landscape shots lit by the full moon). My Canon 40D only shoots well up to ISO 1600, so on that I have to use the 24mm f/1.4 lens, which effectively offers a much more limited 38mm field of view. One of the shots is another moonbow photo, formed by the full moon shining on rain shortly after sunset, captured when I visited California's Anza Borrego State Park earlier this year to catch the moon rise.

Don Olson already has his predictions up for 2012, so you can plan ahead for a Yosemite trip to capture this unique spectacle.