The Tiffen 4 x 5.65" Blue 3 Soft Edge Graduated Filter is a soft-edged graduated colour filter that adds a bluish colour to the image, giving a cooling effect to your photographs. The graduated filter design maintains a neutral part of the image, which gives a more realistic appearance while allowing the sky or other bright areas to take on the colour of the density. Density 3 provides less blue tint than the density 4 filter, but more than the density 2 filter. Tiffen filters are manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, and grinding it flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 5.65" / 101.6 x 143.5 mm and has a vertical orientation; which means that the filter's transition line is parallel to the short side of the filter. - The blue tint gives a cooling effect to part of the image. - Soft edge graduation to clear in order to maintain a neutral part of the image. Specifications