Magnesium fluoride (MgF2) or silicon monoxide (SiO) are used as coating materials, with very thin coatings being applied evenly over the surface through such techniques as vacuum deposition or plasma sputtering. However, light is made up of many different wavelengths, and one coating cannot possibly cut out all reflected light. To cut down reflections of light of various wavelengths requires many layers of coatings. Such multilayer coatings are applied to high-end lenses. The technology for applying coatings of over 10 layers has been developed, and Canon's high-end lenses featuring such coatings provide light transmission of 99.9% over a range that extends from ultraviolet to near-infrared light.