The Tiffen 4 x 4" Hard Edge Graduated Neutral Density 0.3 filter is a graduated neutral density filter that helps to specifically darken skies and other bright areas of the image. nnThe filter is denser at the edge and fades towards the centre, with a sharp transition line between the dense and clear areas. Neutral density filters do not affect the colouration of the image and the 0.3 density provides a 1-stop reduction of 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 pieces of optical glass and polishing 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- 0.3 Soft Edge graduated ND filter for darkening skies and other bright areas of the image.n- Provides a 1-stop reduction of 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.