The B + W filters are made of brass alloy with excellent physical properties and high-purity, distortion-free, thick Schott glass, with a particularly precise design, state-of-the-art manufacturing technology and the highest quality standards. Finally, different types of surface treatment are provided to complete the perfection of B + W filters. From the raw materials used to the final touches, 100% "Made in Germany". B + W circular polarizing filters (factory code: S03) radically reduce reflections and increase image saturation. The polarizing filter is an almost indispensable accessory for outdoor photography. To achieve optimal performance, the filter must be adjusted by turning the outer part. You can check the correct position in the search image. When used, the natural blue of the sky becomes visible, white clouds appear. By excluding the reflection of the water surface or glass surfaces, the contents behind them can also be photographed. This filter is provided with a single surface treatment on both sides. This filter is made with an F-pro socket, which is a standard B + W socket that is also great for use with wide-angle lenses. They are also equipped with a front thread, so that an additional filter (eg CPL) or accessory can be attached, as well as internal nail lens caps.