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Descripción del sistema SmartView® de Sorin

Paso 4. Para el envío de los datos al centro hospitalario, los LEDs de progre- progre-so se apagan mientras que el botón principal permanece de color verde

8. Conclusión

Autochrome plate

The invention:The first commercially successful process in which a single exposure in a regular camera produced a color image.

The people behind the invention:

Louis Lumière (1864-1948), a French inventor and scientist Auguste Lumière (1862-1954), an inventor, physician, physicist,

chemist, and botanist

Alphonse Seyewetz, a skilled scientist and assistant of the Lumière brothers

Adding Color

In 1882, Antoine Lumière, painter, pioneer photographer, and fa-ther of Auguste and Louis, founded a factory to manufacture photo-graphic gelatin dry-plates. After the Lumière brothers took over the factory’s management, they expanded production to include roll film and printing papers in 1887 and also carried out joint research that led to fundamental discoveries and improvements in photo-graphic development and other aspects of photophoto-graphic chemistry.

While recording and reproducing the actual colors of a subject was not possible at the time of photography’s inception (about 1822), the first practical photographic process, the daguerreotype, was able to render both striking detail and good tonal quality. Thus, the desire to produce full-color images, or some approximation to realistic color, occupied the minds of many photographers and in-ventors, including Louis and Auguste Lumière, throughout the nineteenth century.

As researchers set out to reproduce the colors of nature, the first process that met with any practical success was based on the addi-tive color theory expounded by the Scottish physicist James Clerk Maxwell in 1861. He believed that any color can be created by adding together red, green, and blue light in certain proportions.

Maxwell, in his experiments, had taken three negatives through screens or filters of these additive primary colors. He then took slides made from these negatives and projected the slides through 88

the same filters onto a screen so that their images were superim-posed. As a result, he found that it was possible to reproduce the ex-act colors as well as the form of an object.

Unfortunately, since colors could not be printed in their tonal relationships on paper before the end of the nineteenth century, Autochrome plate / 89

Antoine Lumière and Sons

Antoine Lumière was explosive in temperament, loved a good fight, and despised Americans. With these qualities—and his sons to take care of the practicalities—he turned France into a leader of the early photography and film industries.

Lumière was born into a family of wine growers in 1840 and trained to be a sign painter. Bored with his job, he learned the new art of photography, set up a studio in Lyon, and began to experiment with ways to make his own photographic plates.

Failures led to frustration, and frustration ignited his temper, which often ended in his smashing the furniture and glassware nearby. His sons, Auguste, born 1862, and Louis, born 1864, came to the rescue. Louis, a science whiz as a teenager, suc-ceeded where his father had failed. The dry plate he invented, Blue Label, was the most sensitive yet. The Lumières set up a factory to manufacture the plates and quickly found them-selves wealthy, but the old man’s love of extravagant spending and parties led them to the door of bankruptcy in 1882. His sons had to take control to save the family finances.

The father, an ardent French patriot, soon threw himself into a new crusade. American tariffs made it impossible for the Lumières to make a profit selling their photographic plates in the United States, which so angered the old man that he looked for revenge. He found it in the form of Thomas Edi-son’s Kinetoscope in 1894. He got hold of samples, and soon the family factory was making motion picture film of its own and could undersell Edison in France. Louis also invented a projector, adapted from a sewing machine, that made it possible for movies to be shown to audiences.

Before Antoine Lumière died in Paris in 1911, he had the sat-isfaction of seeing his beloved France producing better, cheaper photographic products than those available from America, as well as becoming a pioneer in film making.

Maxwell’s experiment was unsuccessful. Although Frederick E.

Ives of Philadelphia, in 1892, optically united three transparencies so that they could be viewed in proper alignment by looking through a peephole, viewing the transparencies was still not as simple as looking at a black-and-white photograph.

The Autochrome Plate

The first practical method of making a single photograph that could be viewed without any apparatus was devised by John Joly of Dublin in 1893. Instead of taking three separate pictures through three colored filters, he took one negative through one filter mi-nutely checkered with microscopic areas colored red, green, and blue. The filter and the plate were exactly the same size and were placed in contact with each other in the camera. After the plate was developed, a transparency was made, and the filter was perma-nently attached to it. The black-and-white areas of the picture al-lowed more or less light to shine through the filters; if viewed from a proper distance, the colored lights blended to form the various col-ors of nature.

In sum, the potential principles of additive color and other meth-ods and their potential applications in photography had been dis-covered and even experimentally demonstrated by 1880. Yet a prac-tical process of color photography utilizing these principles could not be produced until a truly panchromatic emulsion was available, since making a color print required being able to record the primary colors of the light cast by the subject.

Louis and Auguste Lumière, along with their research associate Alphonse Seyewetz, succeeded in creating a single-plate process based on this method in 1903. It was introduced commercially as the autochrome plate in 1907 and was soon in use throughout the world. This process is one of many that take advantage of the lim-ited resolving power of the eye. Grains or dots too small to be recog-nized as separate units are accepted in their entirety and, to the sense of vision, appear as tones and continuous color.

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Impact

While the autochrome plate remained one of the most popular color processes until the 1930’s, soon this process was superseded by subtractive color processes. Leopold Mannes and Leopold Godowsky, both musicians and amateur photographic researchers who eventu-ally joined forces with Eastman Kodak research scientists, did the most to perfect the Lumière brothers’ advances in making color photography practical. Their collaboration led to the introduction in 1935 of Kodachrome, a subtractive process in which a single sheet of film is coated with three layers of emulsion, each sensitive to one primary color. A single exposure produces a color image.

Color photography is now commonplace. The amateur market is enormous, and the snapshot is almost always taken in color. Com-mercial and publishing markets use color extensively. Even photog-raphy as an art form, which was done in black and white through most of its history, has turned increasingly to color.

See also Color film; Instant photography; Xerography.

Further Reading

Collins, Douglas. The Story of Kodak. New York: Harry N. Abrams, 1990.

Glendinning, Peter. Color Photography: History, Theory, and Darkroom Technique. Englewood Cliffs, N.J.: Prentice-Hall, 1985.

Lartigue, Jacques-Henri, and Georges Herscher. The Autochromes of J. H. Lartigue, 1912-1927. New York: Viking Press, 1981.

Tolstoy, Ivan. James Clerk Maxwell: A Biography. Chicago: University of Chicago Press, 1982.

Wood, John. The Art of the Autochrome: The Birth of Color Photography.

Iowa City: University of Iowa Press, 1993.

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