Neutral Density filters are important tools for controlling light reduction. They permit less depth of field under bright lighting since the aperture has to be larger and, in addition, they permit long time exposures with stronger ND filters in sunlight.
With digital imaging over exposure can be avoided resulting in natural color reproduction. ND gray filters are manufactured from color neutral Schott glass so they can be used for color imaging. They are available in 3 densities. Higher densities are available on special order for technical and scientific applications.