Schneider filters are diamond cut from crystal –clear, water-white optical glass. They are ground and polished to a precise flatness and plane-parellism. Then, a laser interferometer is used to verify them to perfection. Schneider filters are also checked with a densitometer for consistent density, and tested with a spectrophotometer. Because all Schneider filters are designed and manufactured with the highest possible degree of consistency, you can swap like filters mid-shoot with no discernible variation in colour or effect. Schneider filters stand up to the most rigorous demands on the stage and on location, allowing you to shoot with total confidence.