This B+W XS-Pro MRC-Nano 802 Solid Neutral Density 0.6 Filter is a ND filter which has filter factor of 4x which provided 2 stops explosure reduction. It creates a darkening of the whole image by its 06 density which allow you to photograph with a wider aperture than normally required. The coating includes a multi layer and anti reflective part with seven layers on each side of filter in order to prevent divert reflections.