WHAT IT IS
A circular polarizing filter removes light perpendicularly polarized to the axis of the filter. It reduces reflections from some surfaces, it can darken the sky, and it adds contrast the image by eliminating reflections.
WHY YOU SHOULD USE ONE
Cars are giant reflective surfaces, for the most part. Everything that reflects light, reflects it directly onto the paint, chrome, and windows of the car. These reflections are distracting, and reduce contrast in many cases. A CPL lets you reduce or eliminate the worst of the reflections, and improves the look of the photo.
I use it to remove reflections from the windshield, and sometimes reflections from the ground on the side of the car.
HOW TO USE IT
Quick Tip: Polarizers are most effective when the sun is 90 degrees away from what you are photographing – to your left or right.
It’s easier to show you, rather than tell you. Watch this video from Hoya on YouTube.
BLENDING CPL SHOTS TOGETHER
Now that you see how to rotate it to where you need it to be, and how to shoot with it, let’s look at what you can do when you blend 5 different shots together, each of which use the CPL in a different position.