The 4 x 5.65" Formatt-Hitech Soft-Edge Horizontal Graduated ND Glass Filter helps to specifically darken skies and other bright areas of the image. The filter is densest at the edge and tapers to clear by the middle, with a soft-edge transition line between the density and clear areas. By having only a portion of neutral density on the filter, you can selectively darken areas of an image while allowing the portion of the image within the clear section to receive the normal amount of exposure. Neutral density filters do not affect the coloration of the image and the 0.3 density provides a 1-stop reduction in light from entering the lens.
Formatt-Hitech glass filters are constructed from high-quality Schott Superwite glass for exceptional clarity and maintained light transmission. This filter is compatible with the Formatt Hitech 100mm Filter Holder and measures 4 x 5.65" / 101.6 x 143.5mm. The horizontal orientation designation means this filter's line of transition runs parallel to the long side of the filter.