The Autochrome Lumière is an early color photography

Color photography

Color photography is photography that uses media capable of representing colors, which are traditionally produced chemically during the photographic processing phase...

 process. Patented in 1903 by the Lumière brothers in France and first marketed in 1907, it was the principal color photography process in use before the advent of subtractive color film

Photographic film

Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...

 in the mid-1930s.

Structure and use

Autochrome is an additive color

Additive color

An additive color model involves light emitted directly from a source or illuminant of some sort. The additive reproduction process usually uses red, green and blue light to produce the other colors. Combining one of these additive primary colors with another in equal amounts produces the...

 "mosaic screen plate" process. The medium consists of a glass plate coated on one side with a random mosaic of microscopic grains of potato starch

Potato starch

Potato starch is starch extracted from potatoes. The cells of the root tubers of the potato plant contain starch grains . To extract the starch, the potatoes are crushed; the starch grains are released from the destroyed cells...

 dyed red-orange, green and blue-violet (an unusual but functional variant of the standard red, green and blue additive colors) which act as color filters. Lampblack

Soot

Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...

 fills the spaces between grains, and a black-and-white panchromatic

Panchromatic

Panchromatic film is a type of black-and-white photographic film that is sensitive to all wavelengths of visible light. A panchromatic film therefore produces a realistic reproduction of a scene as it appears to the human eye. Almost all modern photographic film is panchromatic, but some types are...

 silver halide

Silver halide

A silver halide is one of the compounds formed between silver and one of the halogens — silver bromide , chloride , iodide , and three forms of silver fluorides. As a group, they are often referred to as the silver halides, and are often given the pseudo-chemical notation AgX...

 emulsion

Emulsion

An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...

 is coated on top of the filter layer.
Unlike ordinary black-and-white plates, the Autochrome was loaded into the camera with the bare glass side facing the lens, so that the light passed through the mosaic filter layer before reaching the emulsion. The use of an additional special orange-yellow filter in the camera was required, to block ultraviolet light and restrain the effects of violet and blue light, parts of the spectrum to which the emulsion was overly sensitive.
Because of the light loss due to all the filtering, Autochrome plates required much longer exposures than black-and-white plates and films, which meant that a tripod or other stand had to be used and that it was not practical to photograph moving subjects. The plate was reversal-processed into a positive transparency

Transparency (photography)

In photography, a reversal film is a type of photographic film that produces a positive image on a transparent base. Also known as dias or slide. The film is processed to produce transparencies or diapositives instead of negatives and prints...

 — that is, the plate was first developed into a negative image but not "fixed", then the silver forming the negative image was chemically removed, then the remaining silver halide was exposed to light and developed, producing a positive image.
Each starch grain remained in alignment with the corresponding microscopic area of emulsion coated over it. When the finished image was viewed by transmitted light, each bit of the silver image acted as a valve, allowing more or less light to pass through the corresponding colored starch grain, recreating the original proportions of the three colors. At normal viewing distances, the light coming through the individual grains blended together in the eye, reconstructing the color of the light photographed through the filter grains.

Manufacturing techniques

To create the Autochrome color filter mosaic, a thin glass plate was first coated with a transparent adhesive layer. The dyed starch grains were graded to between 5 and 10 micrometers in size and the three colors were thoroughly intermingled in proportions which made the mixture appear gray to the unaided eye. They were then spread onto the adhesive, creating a layer with approximately 4,000,000 grains per square inch but only one grain thick. The exact means by which significant gaps and overlapping grains were avoided still remains unclear. It was found that the application of extreme pressure would produce a mosaic that more efficiently transmitted light to the emulsion, because the grains would be flattened slightly, making them more transparent, and pressed into more intimate contact with each other, reducing wasted space between them. As it was impractical to apply such pressure to the entire plate all at once, a steamroller approach was used which flattened only one very small area at a time. Lampblack

Carbon black

Carbon black is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of amorphous carbon that has a high surface-area-to-volume ratio, although its...

 was used to block up the slight spaces that remained. The plate was then coated with shellac

Shellac

Shellac is a resin secreted by the female lac bug, on trees in the forests of India and Thailand. It is processed and sold as dry flakes , which are dissolved in ethyl alcohol to make liquid shellac, which is used as a brush-on colorant, food glaze and wood finish...

 to protect the moisture-vulnerable grains and dyes from the water-based gelatin emulsion, which was coated onto the plate after the shellac had dried. The resulting finished plate was cut up into smaller plates of the desired size, which were packaged in boxes of four. Each plate was accompanied by a thin piece of cardboard colored black on the side facing the emulsion. This was to be retained when loading and exposing the plate and served both to protect the delicate emulsion and to inhibit halation

Anti-halation backing

An anti-halation backing is a layer found in most photographic films. It is usually a coating on the back of the film base, but sometimes it is incorporated between the light-sensitive emulsion and the base. The light that passes through the emulsion is absorbed by the anti-halation layer...

.

The 1906 U.S. patent describes the process more generally: the grains can be orange, violet, and green, or red, yellow, and blue (or "any number of colors"), optionally with black powder filling the gaps.

Viewing techniques

Because the presence of the mosaic color screen made the finished Autochrome image very dark overall, bright light and special viewing arrangements were needed for satisfactory results.

Stereoscopic Autochromes were especially popular, the combined color and depth proving to be a bewitching experience to early 20th Century eyes. Usually of a small size, they were most commonly viewed in a small hand-held box-type stereoscope. Larger, non-stereoscopic plates were most commonly displayed in a diascope, which was a folding case with the Autochrome image and a ground glass diffuser fitted into an opening on one side, and a mirror framed into the other side. The user would place the diascope near a window or other light source so that light passed through the diffuser and the Autochrome, and the resulting back-lit, dark-surrounded image would be viewed in the mirror. Slide projectors, then known as magic lantern

Magic lantern

The magic lantern or Laterna Magica is an early type of image projector developed in the 17th century.-Operation:The magic lantern has a concave mirror in front of a light source that gathers light and projects it through a slide with an image scanned onto it. The light rays cross an aperture , and...

s and stereopticon

Stereopticon

A stereopticon is a slide projector or "magic lantern", which has two lenses, usually one above the other.These devices date back to the mid 19th century, and were a popular form of entertainment and education before the advent of moving pictures...

s, were a less common but especially effective display technique, more suitable for public exhibitions. Unfortunately, projection required an extremely bright and therefore hot light source (a carbon arc

Arc lamp

"Arc lamp" or "arc light" is the general term for a class of lamps that produce light by an electric arc . The lamp consists of two electrodes, first made from carbon but typically made today of tungsten, which are separated by a gas...

 or a 500 watt bulb

Incandescent light bulb

The incandescent light bulb, incandescent lamp or incandescent light globe makes light by heating a metal filament wire to a high temperature until it glows. The hot filament is protected from air by a glass bulb that is filled with inert gas or evacuated. In a halogen lamp, a chemical process...

 were typical) and could visibly "fry" the plate if continued for more than two or three minutes, causing serious damage to the color. More than a few surviving Autochromes suffer from such "tanning" and conventional projection is not a recommended means of displaying these irreplaceable images today.

However, a projector-like optical system (i.e., using condenser lenses for illumination, with a viewing lens in place of the projection lens), employing daylight (not direct sunlight) for the light source, can produce comparably excellent visual results -- although for only one viewer at a time -- without the unacceptable hazards of actual projection.

The use of a "light box" or similar highly diffused artificial light source for viewing Autochromes, although now nearly universal, is unfortunate, as the heavy scattering of light within and among the several layers of coatings on the plate degrades the color saturation. The slight pinkish tinge caused by colloidal scattering (the effect seen through a glass of water into which a couple of drops of milk have been mixed) is exacerbated, and the use of artificial light -- especially fluorescent light -- upsets the color rendition of a system which the Lumière Brothers carefully balanced for use with natural daylight.

Making modern film or digital copies of Autochromes introduces other problems, because a color system based on red, green and blue is being used to copy an image which exists in a red-orange, green and blue-violet system, providing further opportunities for color degradation. Vintage reproductions of Autochromes in old books and magazines have often been noticeably hand-adjusted by the photoengravers in an effort to compensate for some of the difficulties of reproduction, and as a result they sometimes look more like hand-colored photographs than "natural color" ones. In short, it is very difficult to form an accurate impression of the appearance of any Autochrome image without seeing the original "in person" and correctly illuminated.

Artistic considerations

If an Autochrome was well made and has been well preserved, color values can be very good. The dyed starch grains are somewhat coarse, giving a hazy, pointillist effect, with faint stray colors often visible, especially in open light areas such as skies. The smaller the image, the more noticeable these effects are. The resulting "dream-like" impressionist quality may have been one reason behind the enduring popularity of the medium even after more starkly realistic color processes had become available.

Although difficult to manufacture and relatively expensive, Autochromes were relatively easy to use and were immensely popular among enthusiastic amateur photographers -- at least, among those who could bear the cost and were willing to sacrifice the convenience of hand-held "snapshooting" in black-and-white. However, Autochromes failed to sustain the initial interest of more serious "artistic" practitioners, largely due to their inflexibility. Not only did the need for diascopes and projectors make them extremely difficult to publicly exhibit, they allowed little in the way of the manipulation

Photo manipulation

Photo manipulation is the application of image editing techniques to photographs in order to create an illusion or deception , through analog or digital means.- Types of digital photo manipulation :...

 much loved by aficionados of the then-popular Pictorialist approach.http://www.nationalmediamuseum.org.uk/autochrome/pdfs/Autochromes%20-%20Dawn%20of%20Colour%20-%20essay.pdf

Advent of film-based versions

Autochromes continued to be produced as glass

Glass

Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...

 plates into the 1930s, when film-based versions were introduced, first Lumière Filmcolor sheet film in 1931, then Lumicolor roll film in 1933. Although these soon completely replaced glass plate Autochromes, their triumph was short-lived, as Kodak and Agfa soon began to produce multi-layer subtractive color films (Kodachrome

Kodachrome

Kodachrome is the trademarked brand name of a type of color reversal film that was manufactured by Eastman Kodak from 1935 to 2009.-Background:...

 and Agfacolor Neu

Agfacolor

thumb|An Agfacolor slide dating from the early 1940s. While the colors themselves hold up well after 60 years, damages visible include dust and [[Newton's rings]].Agfacolor is a series of color photographic products produced by Agfa of Germany...

 respectively) of the general type still in use today. Nevertheless, the Lumière products had a devoted following, above all in France, and their use persisted long after modern color films had become available. The final version, Alticolor, was introduced in 1952 and discontinued in 1955, marking the end of the nearly fifty-year-long public life of the Autochrome.

Important Autochrome collections

Between 1909 and 1931, a collection of 72,000 Autochrome photographs, documenting life at the time in 50 countries around the world, was created by French banker Albert Kahn

Albert Kahn (banker)

Albert Kahn was a French banker and philanthropist. He was born Abraham Kahn at Marmoutier, Bas-Rhin, France on 3 March 1860, into a Jewish family, one of 5 children of his parents, Louis and Babette Kahn. He died at Boulogne-Billancourt, Hauts-de-Seine, France on 14 November 1940.In 1879 Kahn...

. The collection, one of the biggest of its kind in the world, is housed in The Albert Kahn Museum on the outskirts of Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

. A new compilation of images from the Albert Kahn collection was published in 2008.

The National Geographic Society

National Geographic Society

The National Geographic Society , headquartered in Washington, D.C. in the United States, is one of the largest non-profit scientific and educational institutions in the world. Its interests include geography, archaeology and natural science, the promotion of environmental and historical...

 made extensive use of Autochromes and other mosaic color screen plates for over twenty years. Many thousands of original Autochrome plates are still preserved in the Society's archives.

In the U.S. Library of Congress

Library of Congress

The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

's huge collection of American Pictorialist photographer Arnold Genthe

Arnold Genthe

Arnold Genthe was a photographer, best known for his photos of San Francisco's Chinatown, the 1906 San Francisco Earthquake and his portraits of noted persons, from politicians and socialites to literary figures and entertainment celebrities.-Biography:Genthe was born in Berlin, Prussia, to Louise...

's work, 384 of his Autochrome plates were among the holdings as of 1955.

Neo-Autochromists

In recent years, there has been a revival of interest in the process by some groups. Groups in France, working with the original Lumiere machinery and notes, and a few individuals in the United States, are attempting to recreate the process. Very few complete successes have resulted. Recently, the process was recreated by the photographer Frédéric Mocellin.

In popular culture

• The 2006 film The Illusionist tried to recreate the look of Autochrome, although apparently basing that "look" on published reproductions rather than on actual Autochrome plates.

• Modern image sensor
  Image sensor
  An image sensor is a device that converts an optical image into an electronic signal. It is used mostly in digital cameras and other imaging devices...
  
  s in digital cameras most commonly use a Bayer filter
  Bayer filter
  A Bayer filter mosaic is a color filter array for arranging RGB color filters on a square grid of photosensors. Its particular arrangement of color filters is used in most single-chip digital image sensors used in digital cameras, camcorders, and scanners to create a color image...
  
  , which works in essentially the same way as the colored starch grains in an Autochrome plate -- by breaking up the image into microscopically small color-filtered elements. In physical arrangement, however, the Bayer filter mosaic much more closely resembles the regular geometric pattern used in other color screen plates of the Autochrome era, such as the Paget and Finlay plates.

• Vladimír Jindřich Bufka
  Vladimír Jindřich Bufka
  Vladimír Jindřich Bufka was a Czech photographer and popularizer of photography as well as an important exponent of pictorialism in Czech photography during the early 20th century...
  
   was a pioneer and popularizer of Autochrome in Bohemia
  Bohemia
  Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
  
  .

External links

• The Albert Kahn website
• 1907-1935: Universal Polychrome Overview
• Autochrome: Beauty in Colored Pointillism
• Original instruction booklet (1908)
• Photographs of World War I in color
• The Albert-Kahn Museum Official Web site
• Autochromes (including World War I) et al by Jean-Baptiste Tournassoud (some errors in Autochrome historical information)
• Autochromes from Belgium
• Presentation of Czech Autochrome