The traditional use for circular polarizer in photography is for enhancing colors, reducing reflections on water, and cutting through glare on wet rocks. Here’s another great way to use a circular polarizer. Under right conditions, a circular polarizer can help intensify the colors of the rainbow. I used a circular polarizer to capture this shot from Niagara Falls in New York. In order to get such intense colors, I rotated the circular polarizer while looking through the view finder until the colors of the rainbow were at their brightest.
Rainbows are produced by white sunlight that is being scattered by water droplets in the air, so it’s important to realize that a circular polarizer can also reduce the intensity of the colors in the rainbow… or even remove it completely! I took this second shot at the same location on the same day – but I set my polarizer incorrectly to show the effect. The rainbow is barely visible in this second shot.
Use a circular polarizer to bring out those beautiful colors in the rainbow… but pay attention! Make sure the filter is rotated properly before taking your shot!