The Formatt Hitech’s Firecrest Ultra Cinema ND 2.1 Filter is a high-quality 4 x 5.65″ filter that uses a rare earth mineral coating to create hyper neutral NDs. The filter is constructed with 4mm thick Schott Superwite glass, and the multi-coating is bonded in the middle to enhance its scratch resistance. The Firecrest Ultra Cinema ND 2.1 Filter is neutral across all spectrums, including UV, visible, and infrared, making it an excellent choice for professional photographers and videographers who require accurate and consistent color rendering.Firecrest Ultra IRND are carbon-based IRND filters with hyper-neutral color balance which can be used for uniform near infrared filtration allowing your camera’s color science to remain untouched. Ultra IRND are equally compatible with ARRI, RED, Blackmagic Design, Canon, Panasonic, and other modern digital cinema cameras allowing the image to be captured as the manufacturer intended.4mm Cine Firecrest Ultra IRND have the same features of the popular 4mm Cine Firecrest ND. Firecrest Cine filters were renamed in 2019 to match the Ultra photography filters which received a new lap and polish manufacturing technique. For cinema sizes, the 4mm Firecrest ND were always lapped and polished where the 2mm photography versions were not. 4mm Firecrest ND and 4mm Firecrest Ultra IRND both have identical optical performance with the engraving being the only difference.