I just got back from a quick trip to Yosemite National Park.  This is an amazing time to go: there are blooming dogwoods, roaring waterfalls, snow in the high country and even the occasional redbud.  The best part was a chance to shoot Yosemite Falls by the light of the full moon and catch the moonbow  (See "Yosemite" image tab).

The moonbow is interesting to shoot because:
  • You can't see the moonbow with the naked eye.  Only a long camera exposure can pick it up.
  • Because you can't see it, you can't be absolutely sure when it is present.
  • Exposure is by dead reckoning as you are doing bulb exposures of around 4 to 6 minutes.  Believe your histogram.
April and May are the best months to capture the moonbow. The best times are the night of the full moon and they day before.  I took the image you see from a meadow in Yosemite Valley.  The next night I ran into at least four people hiking up to the base of Upper Yosemite Falls to catch it there.  I also heard from several people that the moonbow was so intense at the Lower Yosemite Falls that it was clearly visible to the naked eye.

On my last morning, I took off on the trail to Vernal and Nevada Falls.  I was just wandering to see what I would see and had no intention of hiking far.  Before I knew it, I was climbing through the spray at Vernal Fall.  I expected it to be too cold but the day warmed up quickly and the spray was refreshing.  The chance to photograph the roaring fall and the intense rainbows was just too much to pass up.  The "Emerald Pools" are anything but right now.  They are raging white water rather than the placid emerald pools you might see in October.