This B+W F-Pro Kaesemann High Transmission MRC Circular Polariser Filter reduces reflections of non-metallic surfaces and increases colour saturation and contrast. For this high-end polarising filter the foil pieces are selected individually for maximum colour neutrality. Following cementing between high-grade optical glass, additional grinding and polishing takes place. This guarantees outstanding sharpness even with very bright, apochromatic lenses. The latest cementing technique ensures lasting stability even in damp climates. The new generation of Kaesemann High Transmission (HTC) polarising filters are fitted with a new polarising foil which has higher light transmission, yet still provides outstanding effectiveness. The filter light loss factor is only 2 to 3, equivalent to approx. 1 to 1.5 f-stops as opposed to up to 3 stops with standard polarisers.
The MRC Multi-Resistant Coating 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 standard B+W F-Pro filter mount, which has a front accessory thread and is made of brass. The F-Pro mount can be used with wide angle lenses, including most 24mm focal lengths on a full frame body, without vignetting. Another advantage of the F-Pro mount is it's modified retaining ring, which is no longer threaded in from the front, but holds the filter glass in place from the back. When removing a filter or lens hood that has been screwed on too tight to the filter, the retaining ring is not at risk of loosening.