Quote Originally Posted by Flaming
I don't know too much but the couple of rainbows that I have shot I have used a circular polarizer. It might not make too much of a difference, but it makes it pop a little nicer. Here is one I took in my pre d-slr days. It is not the best but I think it shows how the polarizer can help with the pop of the rainbow.

I'm glad you posted that. I was wondering how a circular polarizer would look when shooting a rainbow...