Soft Edge graduated filters transition gradually in density from the top of the filter toward the center, and although there is a horizon line, it is subtle. This allows for horizon transitions to be more easily hidden in a scene, especially with an undulating horizon line such as mountains, buildings or trees. Typically graduated filters are used to enhance the sky by balancing the luminosity of the sky to the luminosity of the terrain. Firecrest ND is a quantum leap improvement over all previous generation ND and IRND products and represents the technological state of the art in scientific light modification. These glass filters are hyper-neutral across the visible light spectrum and also remove more IR contamination than any other filter - making them IRND filters. The Firecrest coating is sandwiched between the finest Schott Superwite optical glass, increasing scratch resistance and longevity. Firecrest reduces all spectrums of light (UV, visible, near infrared and infrared) almost perfectly evenly. With the Firecrest coating safely sandwiched into the middle of the filter, the outside of the filters are lapped and polished to the high tolerances in the industry. Extremely flat filters are important because any flaw in the surface will be revealed as distortion in the image while panning through a shot. Another industry first with Firecrest ND is the development of IRND grads. Legacy graduated ND filters are manufactured from the traditional ND formulations originally developed for use with film and do not reduce infrared. Firecrest ND grads use the same Firecrest technology as their solid ND brothers. The result is a perfectly neutral graduated ND filter that pairs and stacks perfectly with even the highest densities of ND filter, and especially with other Firecrest ND filters.