To check out the effect on reflections, find a dark shiny car and stand three-quarters view to the front. Rotate the filter (you don't need a camera for this) and watch how the reflections on the windscreen and bonnet change, and note the position of the mark on the ring. Now turn that ring through 90 degrees and you'll see the reflections on the bonnet have returned, but those along the sides have vanished.
I thought that reflections from metallic surfaces weren't polarised, so it shouldn't have an affect on a car?
It's got paint on it, which insulates the electro-magnetic properties of the metal. Won't work on chrome though![]()