These professional quality filters are made in Japan using precision optical glass that is carefully smelted and blended to yield perfect optical results. Hoya has applied the same care and precision to the multi-coating process, using an improved Super Multi-Coating (IS-HMC) formula to greatly reduce or eliminate reflections off the surface of the glass. These coating are overlaid with a clear water & stain resistant coating that is easy to clean. This makes for easier care and handling of the filter in the field. All coating layers are applied in a furnace to bond the coating to the glass.