The Hoya HRT Circular Polarizing (Cir-PL) Ultraviolet (UV) Multi-Coated Filters eliminate reflections from nonmetallic surfaces and increases contrast and color saturation such as water and glass. This filter uses a newly developed High-Rate Transparency film that passes more visible light through the filter while still filtering the same amount of polarized light. The HOYA HRT circular polarizer filter transmits as much as 25% more light through the polarizing film giving the photographer about 1/3 stop more light than a standard circular polarizer. The HRT polarizer, which combines a UV Filter with the latest generation in circular polarizing films, apparently developed for 3D cinema glasses. The result is a lighter tint in the filter as it lets more light through and also less of a blue cast, while the UV filtration moderates blue cast. Hoya HRT Cir-PL UV filters are optimized for use with digital SLR cameras, but they are also perfect for traditional 35mm SLR applications, including black and white photography. Key Features: High-Rate Transparency Film - Transmits as much as 25% more light through the polarizing film giving the photographer about 1/3 stop more light than a standard circular polarizer. Slim Rotating Frame - Fitted in a slim rotating 5mm ring, it will be invaluable to landscape and other photographers who need avoid vignetting with wide angle lenses Protected Case Included Benefits of Using Hoya HRT Filters: HRT polarizers cost a lot less than the HD filters, and offer the same high quality polarizing material. This special high-transparency material is that it transmits about a stop more light than other polarizers, which just gave you an extra stop of ISO at no charge. The polarization effect is just as strong.