I've read more than once, from reputable sources, that a polarizer filter can be used to enhance a rainbow. I don't believe it. A polarizer can erase a rainbow, but as far as I can tell, no matter how you turn it, a polarizer doesn't enhance a rainbow any more than if the filter were removed.
What's your opinion? Can somebody show me some reliable evidence that a polarizer can make a rainbow appear more vivid?
All I have is anecdotal evidence that yes indeed, polarizers most certainly do enhance rainbows. I've seen it with my own eyes many, many times. If you can't believe 'reputable sources', then simply don't use one.
I usually don't use a polarizer for rainbows, but occasionally the filter is on the lens when a rainbow appears. I can't see that the polarizer does any good, but it certainly is capable of decreasing the vividness.
So, I'm thinking of making some comparison images, with filter and without filter, at the next opportunity.
My experience is similar to John's. There are times when a polarizing filter most definitely enhances the apparent saturation and intensity of a rainbow. And also, as you have seen, it is capable of killing the vividness as well. Technically, it may be that the polarizer is actually having more of an effect on the surrounding sky, and thereby giving the impression that it is enhancing the rainbow.
I think so much depends on the shooting angle. Polarizers are most effective when you are pointing 90 degrees off from the sun angle. I'm guessing that might have something to do with the differing results people are seeing.
I'm hardly a landscape photo expert, but I certainly noticed an enhancement when I was shooting a rainbow at Yellowstone Falls with a polarizer this spring. I would have assumed, as Keith said, that the angle plays a big role.
I've seen rotating a polarizer change the apparent brightness of a rainbow many times. I think it's largely a case of how it brightens or darkens the surrounding sky. The size of the drop may play a role here, since millimeter and larger size drops oscillate in shape as they fall while smaller ones stay round. It cannot be an issue of angle because the primary rainbow only occurs at an angle of 42 degrees around the line between the sun and the camera (or your head) and the secondary bow (if you have one) occurs at 51 degrees from the anti-solar point.
Discussion
6 repliesWhat's your opinion? Can somebody show me some reliable evidence that a polarizer can make a rainbow appear more vivid?
I usually don't use a polarizer for rainbows, but occasionally the filter is on the lens when a rainbow appears. I can't see that the polarizer does any good, but it certainly is capable of decreasing the vividness.
So, I'm thinking of making some comparison images, with filter and without filter, at the next opportunity.
Max