Gabriel Lippmann Jonas Ferdinand Gabriel Lippmann (16 August 1845 – 13 July 1921) was a Franco-Luxembourgish physicist and inventor, and Nobel laureate in physics for his method of reproducing colours photographically based on the phenomenon of interference. ...

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 ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

for this work in 1908. A Lippmann plate is a clear glass plate (having no

anti-halation backing An anti-halation backing is a layer found in many photographic films—and almost all film intended for motion picture cameras—usually a coating on the back of the film base, though it is sometimes incorporated between the light-sensitive photo ...

), coated with an almost transparent (very low silver halide content)

emulsion An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Althoug ...

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.

Method

In Lippmann's method, a glass plate is coated with an ultra fine grain colour-sensitive film using the Albumen Process containing

potassium bromide Potassium bromide ( K Br) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US. Its action is due to the bromide ion (sodium bromide is equall ...

, then dried, sensitized in the silver bath, washed, irrigated with cyanine solution, and dried again. The back of the film is then brought into optical contact with a reflective surface. This is done by mounting the plate in a specialized holder with pure

mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

behind the film. When it is exposed in the camera through the glass side of the plate, the light rays which strike the transparent light-sensitive film are reflected back on themselves and, by interference, create

standing wave In physics, a standing wave, also known as a stationary wave, is a wave that oscillates in time but whose peak amplitude profile does not move in space. The peak amplitude of the wave oscillations at any point in space is constant with respect ...

s. The standing waves cause exposure of the emulsion in diffraction patterns. The developed and fixated diffraction patterns constitute a

Bragg condition In physics and chemistry , Bragg's law, Wulff–Bragg's condition or Laue–Bragg interference, a special case of Laue diffraction X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in ...

in which diffuse, white light is scattered in a specular fashion and undergoes constructive interference in accordance to Bragg's law. The result is an image having very similar colours as the original using a black and white photographic process. For this method Lippmann won the

in 1908. The colour image can only be viewed in the reflection of a diffuse light source from the plate, making the

field of view The field of view (FoV) is the extent of the observable world that is seen at any given moment. In the case of optical instruments or sensors it is a solid angle through which a detector is sensitive to electromagnetic radiation. Humans a ...

limited, and it cannot be copied. The technique was very insensitive with the emulsions of the time and it never came into general use. Another reason Lippmann's process of colour photography did not succeed can be found in the invention of the autochrome plates by the

Lumière brothers Lumière is French for 'light'. Lumiere, Lumière or Lumieres may refer to: *Lumières, the philosophical movement in the Age of Enlightenment People *Auguste and Louis Lumière, French pioneers in film-making Film and TV * Institut Lumière, a ...

. Lippmann photographic techniques have been proposed as a method of producing images which can easily be viewed, but not copied, for security purposes.

Other sources of Lippmann plates

* The Kodak Spectroscopic Plate Type 649-F is specified with a resolving power of 2000 lines/mm. * A diffusion method for making silver bromide based holographic recording material

References

External links

Lippmann Wiki for experimentersForum for the Lippmann Process
{{DEFAULTSORT:Lippmann Plate Photographic processes