Cokin P164 Circular Polarizer

This is the Circular Polarizer P164 glass filter COKIN. Fits into the optional P COKIN. The rays of light that are reflected are polarized. Polarizing filters are used to select the rays of light entering your camera lens. A polarizer helps to make a bluer blue sky, as well as make the clouds stand out. It can remove unwanted reflections from non-metallic surfaces, such as water or glass and also saturate colors that provide better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies depending on how the filter is rotated and its orientation to the sun.

Note circular polarizers are designed specifically for use with autofocus SLR cameras (which will also work on manual systems without problems)