The Hoya HRT circular polarizer filter allows up to 25% more light to pass through the polarization film, providing the photographer with approximately 1/3 more light than a standard circular polarizer. This new polarization film is also used in the latest HD LCD televisions. The glass of the Hoya HRT filter also has UV-absorbing properties, making the HRT a combined UV/circular polarizing filter. The most common use for a circular polarizer is to enhance the deep blue sky in outdoor photography. However, it can also reduce or eliminate reflections from non-metallic surfaces such as glass and water. By rotating the outer ring, the filter can be viewed through the viewfinder.