Ideal for solar photography, this 4 x 5.65" Firecrest Ultra Cinema ND from Formatt Hitech uses a rare earth mineral coating to create exceedingly neutral NDs. The filter is made from 4mm thick Schott Superwite glass, with a multicoating that is bonded in the middle to increase scratch resistance. Firecrest filters are neutral across all spectrums, including UV, visible, and infrared.