High-grade transparent film. This filter uses a newly developed film (High-Rate Transparency) that allows more visible light to pass through the filter while filtering the same amount of polarized light. The HOYA HRT filter transmits up to 25% more light through the polarizing film, offering photographers about 1/3 stop more light than a standard circular polarizer.

UV absorption. The glass of the HOYA HRT filter has additional ultraviolet absorption properties. The most common use for a circular polarizing filter is to darken a bright blue sky in outdoor photography, but they can also reduce or eliminate reflections from non-metallic surfaces such as glass and water. By rotating the outer ring of the filter, the change can be observed by looking at the filter or through the viewfinder if it is mounted on a camera.