An interference film of the type described by Lippmann was prepared by exposing a high-resolution plate in contact with mercury. The plate was exposed through the back with a helium-neon laser. The processed plate produced a color, by interference, when viewed by specularly reflected white light. The interference color depended on the local humidity and temperature. An infrared image focused by a concave mirror, on this surface changed the spacing of the interfering layers, changed the color, and thus made the infrared image visible. The invisible image could be ultraviolet as well as infrared.