The Tiffen 4x4" Hard Edge Graduated ND Filter is a graduated neutral density filter that 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 hard-edged line of transition between the density and clear areas.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4" / 101.6 x 101.6mm.
Made in the USA!