This 4 x 4" Formatt-Hitech Firecrest Graduated ND Filter Kit contains 5 Firecrest Graduated ND filters, ranging in density from 0.3 to 1.5 to provide a selective reduction in exposure from 1 to 5-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. These filters are 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.
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.
Sandwiched between layers of Schott Superwite glass is a 15-layer Firecrest multi-coating, which helps to minimize reflections and flare in order maintain truer colors and contrast. Since the coating is located within the middle of the filters, they are less prone to scratching or damage and have a more durable and hydrophobic design. Each filter in this kit measures 4 x 4" / 101.6 x 101.6mm and is 0.16" / 4mm-thick.