The Tiffen 4 x 4" ND 0.3 Hard Edge Graduated filter is a graduated neutral density filter that helps to specifically darken skies and other bright areas of the image. nnThe filter is densest at the edge and fades to clear in the middle, with a sharp transition line between the density and clear areas. Neutral density filters do not affect the colouration of the image and the 0.3 density provides a one-stop reduction in light entering the lens.nnThis filter is constructed from Water White glass and manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 optical glass plates and grinding it flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4" / 101.6 x 101.6 mm. nn-Hard Edge Graduated ND 0.3 filter to darken skies and other bright areas of the image.n-Provides a one-stop reduction in light in selected areas.n-Neutral density filters do not affect the overall colouration of the image.n-Water White optical glass for excellent clarity.