Circular Polarizer - Light rays which are reflected become polarized. Polarizing filters are used to select which light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colors providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter. The filter factor varies according to how the filter is rotated and its orientation to the sun.
If you're out walking on a lovely day - in the mountains or at the beach - and you want to get a fabulous shot of a cloud-filled sky or make the water seem more saturated, then a polarizer is the way to go. This filter is the best way to make the clouds stand out, increase or decrease the saturation of the ocean or increase or decrease the reflection off the water. You can also use this filter when shooting into glass or windows since it will, again, either increase or decrease reflections.
If you're shooting black and white and want to simulate a threatening storm, try throwing on a Red filter. The vista will take on the appearance of an imminent, ominous storm.
Along with a UV or Skylight Filter, a polarizing filter should be a part of everyone's gear bag. It can turn a run-of-the-mill image into a stunning, creative photo by increasing color saturation.
The advantage of Hoya filters is that Hoya puts one layer of anti-reflective coating on each side of their glass. It is not bare glass. Even if the glass is not multi-coated, this kind of production tends to minimize flare and ghosting.
Hoya is one of the largest manufacturers of glass in the filter industry. In collaboration with its parent company, Tokina Optical, Hoya continues to strive to produce some of the best glass on the market. Currently, they hold 40% of the world's market for optical glass.
Note! Circular polarizers are specifically designed for use with auto-focus SLR cameras (They will also work on manual systems and video cameras without problems)
58mm Circular Polarizer Filter