Polarising filters are used to select what light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces like water or glass and also saturate colours for better contrast. The effect can be seen through the viewfinder and varied by rotating the filter.
The “high-end” polarizing foils of the Käsemann-type filters are neutral in color, they have a higher efficiency than conventional polarizing foils and they are cemented between high-grade plano-parallel optical glass. The resulting sandwich is then precision-polished again to achieve highly accurate plano-parallel surfaces. Subsequently they are edge-sealed to protect the foil against humidity. They are well suited for applications that require the highest possible imaging quality, especially with high-speed telephoto lenses and apochromatic lenses. The new gerneration of Kasemann High Transmission (HTC) polarizing filters is fitted with a new ploarizing foil which has higher translucency (transmission), yet still provides outstanding effectiveness. The filter extension factor is only 2 to 3, equivalent to approximately 1 to 1.5 f-stops.
Featuring Multi-Resistant Coating (MRC) with Nano Technology, the nano coating is an outer layer of protection that comes standard with all XS-Pro Digital MRC filters. The nanotechnology based characteristic (lotus effect) produces a better beading effect with water making the cleaning of this filter even simpler and faster than ever before. MRC nano has an improved outer (8th) layer over regular MRC. MRC by B+W is not only an extraordinarily effective multiple layer coating, it is also harder than glass, so that it protects filters from scratches (for instance when cleaning the filters), and it is also water and dirt repellent, thus facilitating filter maintenance. This filter uses the XS-Pro Digital mount which is especially suited for DSLRs with wide angle and zoom lenses. It has a front thread for additional accessories such as lens caps or hoods. All XS-Pro Digital mounts are made of brass and are matte black to prevent reflections.