When my wife and I were in the Mammoth Lakes, California area on a recent trip, we made the hike from Devil's Postpile to Rainbow Falls. We had read that in order to see the rainbow, it was necessary to be there in the middle of the day. The only problem was that at that time of day, the area to the right of the falls was in deep shadow. I bracketed the exposure and then combined the images using Photomatix Pro's tonemapping software to give more detail than the camera's sensor is capable of giving. I think it worked OK and, hopefully, doesn't look fake.
To see more of my pictures, taken over the years, in this beautiful part of the world, check my Eastern Sierras set....... www.flickr.com/photos/9422878@N08/sets/72157606897213537/...
Press "L" to view large. Photography does look better large.