The B+W CPL filter is a circular polarizing filter that removes unwanted reflections from non-metallic surfaces , such as water, glass . And they also help increase colour saturation, clarity and contrast. This threaded filter is often used to increase the contrast and saturation in blue sky and white clouds, without affect the overall color balance for a shot. And they will provide protection for your lens while shooting. This filter is recommended for color and black& white film, as well as digital photography.
Light rays which are reflected become polarized. Polarizing filters are used to select which light rays enter your camera lens. They can remove unwanted reflections from non-metallic surfaces such as water or glass and also saturate colors providing better contrast. The effect can be seen through the viewfinder and changed by rotating the filter.
Circular polarizers are specifically designed for use with auto-focus SLR cameras (They will also work on manual systems without problems) and video cameras. It does not influence the metering systems of these cameras. Made in Germany using high quality Schneider optical glass held in place by heavy duty brass rings, these filters are the epitome of quality.
Compared to the earlier B+W standard mount, The B+W Standard Filter Mount F-Pro has been improved considerably. While maintaining the excellent quality of materials, fabrication, and high mechanical stability, the new F-Pro mount has become thinner, so that now it can also be used on many wide-angle lenses without the danger of vignetting. Another advantage of the new F-Pro filter mount is its modified retaining ring, which is no longer threaded in from the front, but holds the filter glass in place from the back. This prevents the retaining ring from being accidentally loosened during the removal of an additional filter or a lens hood that has been screwed in too tightly.