The Hoya HRT Circular Polarizing Filter is unique in its design since it incorporates a High RateTransmission film that permits more visible light to be passed through the filter while still producing the same degree of polarized light. This filter now permits the equivalent of 1/3 stop more light to be taken in yet it still filters the same amount of polarized light. This can be a huge benefit to users of both digital and HD technology cameras and lenses.

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.

This filter also contains UV properties which aid in eliminating the bluish cast on cloudy days or in open shade.

Polarizers should be a part of every photographer's gear. They are useful when you wish to increase the saturation of a blue sky or want to make the clouds stand out more. Moreover, they are handy when reflections are a problem - such as when shooting into glass or on the water. 

All of this goes into increasing contrast for a more effective photo. The effect of the polarization 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.