Firecrest Ultra is a new and improved Firecrest filter. Firecrest Ultra filters are lapped and polished to deliver superb clarity and sharpness at all focal lengths. Bonded to protect the coated in the centre of the filter rather than simply coating the outside - this gives the filter a substantially increased lifespan over coated filters and so represents a better investment. Incredibly neutral across all spectrums, including UV, visible, and infrared. This 100x100mm Firecrest Ultra 0.9 Neutral Density filter reduces light by 3 stops.