The 1.2 graduated neutral density hard edge glass filter Formatt-Hitech 6.6 x 6.6" helps to specifically darken skies and other bright areas of the image. The filter is densest at the edge and fades to become clear in the middle, with a hard edge transition line between the density areas and clear areas. By having only a neutral density portion on the filter, you can selectively darken areas of an image whilst allowing the part of the image in the clear section to receive the normal amount of exposure. Neutral density filters do not affect the colouration of the image and the 1.2 density provides a 4-stop reduction of light entering the lens. Formatt-Hitech glass filters are constructed from high-quality Schott Superwite glass for exceptional clarity and maintained light transmission. This filter measures 6.6 x 6.6" / 167.6 x 167.6mm. - 1.2 hard edge graduated ND filter for darkening skies and other bright areas of the image. - Provides a 4-stop reduction of light in selective areas. - The hard edge transition is ideal for circumstances where there is a clear and distinct separation line between the bright and dark areas of the image. - Neutral density filters do not affect the overall colouration of the image.