The 165 x 200mm Formatt-Hitech Firecrest Graduated ND Filter Kit contains 4 Firecrest graduated ND filters, ranging in density from 0.3 to 1.2 to provide a selective reduction in exposure from 1 to 4 stops. Graduated neutral density filters help to darken specific areas of an image, such as bright skies, while allowing for a normal, unaffected exposure in other regions of the image. The ND effect is densest at the edge and taper to clear by the middle, with a soft-edged line of transition between the density and the clear areas. These filters are designed to be used in the vertical orientation as the line of transition runs parallel to the short side of the filter.
The design of these filters has been optimized for use with digital sensors and promote nearly flat attenuation of visible, UV, and infrared light. Due to imaging sensors' greater susceptibility to infrared light, compared to traditional film, color casts can occur when photographing darker subjects that require increased exposure times. These filters provide a high level of neutrality across all three spectrums in order to eliminate color casts and ensure cleaner, truer blacks.
Applied to the outside of the Schott Superwite glass construction is a 15-layer Firecrest multicoating, which helps to minimize reflections and flare in order maintain truer colors and contrast. The multicoating is also scratch-resistant and hydrophobic to benefit the overall durability of the filters. Each filter in this kit measures 6.5 x 7.9" / 165 x 200mm and is 2mm thick, making it compatible with the Lucroit 165mm Filter Holder.