The Tiffen 77mm Digital High Transmission (DHT) Circular Polarizing Multi-Coated Filter is a filter that contains the strength of a titanium coating along with high-end optical glass. Using their patented ColorCore technology, this filter represents the highest scratch-resistant durability available. There is no need to worry about cleaning this filter since the coating protects the surface thereby maintaining the optical quality of the glass.
This filter has a low profile design as well an extra durable filter ring. The "Wow" feature is that Digital HT filters are rated to surpass military specifications for hardness and durability - no small achievement.
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.