Modern lens coatings?
I became a photography addict when I was a teenager during the late 1940s. At that time I bought a wonderful book titled: "Kodak Reference Handbook," that I still have. In its section on lenses, it calls coated lenses "lumenized" lenses, and says that its (Kodak's) lenses that are lumenized bear the letter L engraved on the mount. It says that the coating is magnesium fluoride (MgF2), that gives the lens a slightly bluish tint for reflected light, but that does not affect its color rendition for transmitted light. It also says that it slightly increases the speed of a lens. My first camera was a Kodak 35mm camera with split image rangefinder. Its lens was "lumenized." Question: is MgF2 still used as lens coating these days, or do they use something else. If so, what? (Just an old curious dodo.)