The b+w 58mm XS-Pro digital ND Varo mrc-nano filter is a solid variable neutral Density filter providing an exposure reduction of 1 to 5 stops. The 0.3 to 1.5 Density creates a darkening of the entire image, allowing you to photograph with a wider aperture or slower shutter speed than normally required. The degree of density is easily controlled by rotating the front filter ring, helping you to predetermine the additional exposure length required. By slowing your exposure time or increasing your aperture, you are able to control depth of field and convey movement more easily. For easier, repeatable control over Density settings, The front ring is also visually demarcated with dots that represent different Density values.The multi-resistant coating (MRC) is both an anti-reflection coating as well as a protective surface. It helps to increase light transmission by reducing reflections, scattered light, and ghosting. Additionally, it offers greater protection to the filter substrate and stays cleaner for longer than uncoated filters. The Nano coating associated with XS-Pro filters provides an additional eighth layer over the MRC, resulting in an improved beading effect when in contact with water for greater cleaning efficiency.B+w filters are constructed from Schott glass for increased optical clarity and color fidelity. This filter features a thin, oversized mount which helps to reduce the likelihood to vignetting when used with wide-angle lenses. The filter ring is made from brass for durability as well as jamming prevention.