Yosemite Falls Moonbow is a rainbow created by the moon rather than the sun. It only happens a few time a year requiring the alignment of a nearly full moon which is at an angle of 42 degrees (the same condition that is required for a rainbow). You can not see it with the naked eye but with a long exposure photograph it is awesome! To the eye it looks like a silver shimmer. Below are two photos I took in on April 15, 2014 between 9pm and 10:30pm.
I start with ISO 800, exposure time 20 sec, and apperature at f2.8. Experiment and shoot at different ISOs. As long as you are not moving the tripod, you can even drop down to a low ISO and shoot a long exposure to use as a foreground image with digital blending. You have to take an exposure and look at it on the camera screen to see the Moonbow. The Moonbow moves with the mist from the falls so take a lot of exposures. It also seems to start high and move lower as the moon moves behind you over the hour or so of shooting.
One of the most surprising things for me was to see that most of the photos looked like they were taken during the day. The only real give away was the sky full of starts! After shooting the Moonbow, go down into the valley floor and take the same photos you would take during the day. You will be surprised at the results.
Things I find helpful:
- Cover camera & lens with cloth when not taking a photo to keep them dry
- Use a large cloth so you can put it over your head when looking at screen to block light
- If wind is blowing, pay attention that things do not get blown away.
- Have more than one dry cloths to keep lens clean from water and mist
- Use a light that only goes red to keep from accidently turning it on white. Consider modifying head light to prevent it going white.
- Practice setting up your camera before you go. Do it in a very dark room.
- Set up the basic items on your camera before you go out in the dark.
- Use a cable release and if you camera has a “mirror up” function use it.
- Go to the shooting location during the day to get the feel of things. Take a few day photos to find the best lens setup for your gear. I only used one lens for the shoot. Changing lens in the dark can have bad consequences.
- If you can, bring a small chair. The shoot will take a lot of time and sitting down is nice, consider setting your tripod/camera low so you can shoot sitting.
As there will most likely be many photographers in the area and few bits of adequate are required:
- Never use a white flashlight. Only use a red light and point it only at your camera. Turn it off when not using it.
- As it will be a full moon, you will be able to see very well without a light except for possibly camera settings.
- Never use a flash. (unless you want to be thrown into the creek by blinded photographers!)
- Cover bright LEDs on your camera with tape so they do not effect others.
- You can see very well, be careful not to trip over someone else’s equipment (or your own)
- If possible cover the display on your camera when checking exposure to avoid blinding someone or creating light flair in their photo.
Best dates for 2016 are:
- Apr 20-22
- May 20-22
- Jun 19-21