Polarizing filters areused to select which light rays enter your camera lens. They canremove unwanted reflections from non-metallic surfacessuch as water orglass. Filter can also saturate colors, providing better contrast.The effect can be seen through the viewfinder and changed byrotating the filter. The filter factor varies according to how thefilter is rotated and its orientation to the sun. Filter factor isbetween 2.3 and 2.8 (approx. +1.3 stops). Typical applicationsinclude darkening skies, water reflection elimination, andwindow/glass/eyeglass reflection elimination.
Circular polarizers are specificallydesigned for use with auto-focus SLR cameras (They will also workon manual systems and video cameras without problems). Linearpolarizers may not work properly with auto-focuscameras.
Optical glassand Anodized Aluminum Metal