The Cavision 3x3" Graduated ND 0.9 Glass Filter is a medium-soft-edged neutral density filter. The dense area helps to darken skies and other bright areas of the image. The filter is most dense at the edge and softly tapers to clear by the middle of the filter. Neutral density filters do not affect the coloration of the image. The 0.9 density provides a 3 stop exposure reduction for holding back bright regions of the image. The filter measures 3x3" / 76.2 x 76.2mm and is constructed from 2mm-thick glass.