I was in Hawaii with the Canon 5D Mark II + 24-70mm F/2.8 and Circular Polarizer last year when I shot this. I was about to trash this video, but then remembers a few friends who had questions "Is a Polarizer worth it?, What do they do?" So here it is peeps and others who might be interested in the Before and After use of Polarizers on Lenses. The video shows the difference in how much contrast and saturation you can obtain. This is not the same as an ND filter that simply blocks light. These circular polarizers are designed to block light from a certain direction, so you turn them in front of the lens depending on the situation. Yes you can use these in combination with ND filters. These are also recommended with normal video camcorders and point and shoot cameras that can accept filters. These are not just for DSLR video and photo cameras. You just have to remember to get the right size for your lens.