Lippmann plate

Gabriel Lippmann conceived a two-step method to record and reproduce colours, variously known as direct photochromes, interference photochromes, Lippmann photochromes, Photography in natural colours by direct exposure in the camera or the Lippmann process of colour photography. Lippmann won the Nobel Prize in Physics for this work in 1908.

A Lippmann plate is a clear glass plate (having no anti-halation backing), coated with an almost transparent (very low silver halide content) emulsion of extremely fine grains, typically 0.01 to 0.04 micrometres in diameter. Consequently, Lippmann plates have an extremely high resolving power exceeding 400 lines/mm.