The Tiffen 4 x 4" 3 Skyfire Graduated Filter helps to specifically add a unique orange to yellow gradient to skies and other bright areas of an image while allowing a portion of the image to remain neutrally colored. The filter's coloring is densest at the edge and tapers to clear by the middle, with a soft-edged transition between the density and clear areas. The 3 color density provides more skyfire coloration than the 2 density filter. 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. It measures 4 x 4" / 101.6 x 101.6mm. Provides a unique orange to yellow gradient across half of the filter plane. Graduated filter design keeps a portion of the image neutral, resulting in a more realistic look while allowing for the sky or other bright areas to take on the color of the density.