The term has a meaning photography triple:
* This is the technique to create images by the action of light.
* This is an image obtained by this technique.
* More generally, the graphic arts industry that uses this technique.
The word "photography" is composed of two Greek roots:
* The prefix "photo" (φωτoς, photos: light, clear) - which carries the light, using light;
* The suffix "-graphy" (γραφειν, graphein: painting, drawing, writing) - who writes, resulting in an image.
Literally "paint with light". The shorter-term picture is very frequently used. In cases where there is talk of a photographic image, it also often employs the terms image, drawing, photography or expansion.
The person using the photographic technique during the shooting is called the photographer. There are many occupations related to the shooting. For example, a person working in a laboratory to carry out the expansion of negatives is called the shooter.
The photographic technique: history
This article traces the milestones that mark the history of photography, mainly seen in its technical aspect.
The photograph can be seen as a technique to replace the drawing or painting to represent the world around us, his invention has taken on the one hand the realization of an optical device to enable the creation of the image, and d ' secondly to set the image on a permanent support by a chemical process irreversible.
Also uses this technique has evolved, and its artistic dimension has been recognized.
Photography as a technique
At the time of the Renaissance, Italian painters begin to discover the laws of perspective. To simplify the layout of their surroundings, they use two optical devices which can be projected onto a surface image of a landscape or an object, clear the room and dark room.
The latter was known to Aristotle (384-322 BC.), The Persian scientist Ibn al-Haytham (965-1038) and by Leonardo da Vinci (1452-1519), and can be regarded as 'ancestor cameras. It consists of a box, sealed in the light of which one side is pierced with a tiny hole, the pinhole. The inverted image of an object illuminated placed outside in front of the hole is formed on the opposite wall.
It was used by many artists, including Giambattista della Porta, Vermeer, Guardi and Giovanni Antonio Canal, known as Canaletto, who used particular perspective to put in his famous landscapes canals of Venice.
Visitors to the Italian physicist Giambattista della Porta (1535 - 1615) would have been frightened by seeing on the wall the image of little people moving upside down. Panicked, they would precipitate out of the room. Della Porta was accused of witchcraft. Della Porta wanted to entertain his guests by having them discover a camera obscura ie the darkroom in Latin.
It can produce a dramatic effect, although its operating principle is simple. When light enters through a tiny hole in a box or dark room, a reversed and inverted image from outside is projected onto the opposite wall. What guests of Della Porta saw was nothing more than the players playing in the next room. What is now called the darkroom was the ancestor of the modern camera.
The dark room was not a novelty at the time of Della Porta. Aristotle (-384 - -322 av. JC) had observed the principle that it would work. Alhazen, an Arabic scholar of the tenth century, gave a detailed description, and the books of the famous Leonardo da Vinci in the fifteenth century, were also mentioned. In the sixteenth century, the sharpness of the image has improved with the introduction of the lens. Many artists have used this incident to make a more accurate view of the scale. Yet, despite multiple attempts, it was not until the nineteenth century to obtain a permanent image.
The main disadvantage of the pinhole is its lack of brightness. Indeed, the definition of the image produced, ie the fineness of detail, is based on the size of the hole. To obtain a sufficiently detailed picture it should be as small as possible, but then he does that very little light and the picture is not visible. A glass lens that can focus light rays, improves the performance of pinhole: the diameter of the opening is more important, it admits more light and the picture is clearer.
The physical device used to create the image being invented, there was an important step: how to ensure that the vision created by the fleeting light in the darkened room is transformed into a real image, stable and sustainable as a drawing or a painting. In other words, how to remove the work of the painter or designer, with all that implies personal interpretation, errors and inaccuracies, and to automatically perform this work by the light itself?
The discovery of the action of light rays on a sensitive surface is attributed to the medieval alchemists, who knew the properties of silver chloride, sensitive to light. It was followed during the seventeenth and eighteenth centuries by various searches (Schulze, Beccaria, Wegwood).
The first photographic image
At the beginning of the nineteenth century Joseph Nicéphore Niépce (1765-1833) managed to obtain and maintain an image caused by the action of light. From 1812, he managed to get in lithography negatives (with silver chloride) and positive (with bitumen of Judea), but these images are not stable.
In 1819, John Herschel describes the properties of the sodium thiosulphate which will become the fixer of Mijus.
The oldest photograph, dated 1825 is a reproduction by Niepce a Dutch engraving representing a small horse and not, as was long believed, the sight of his property of Saint-Loup-de-Varennes (Saone -et-Loire): in 1826 he placed a sheet of tin covered with asphalt in a dark room, facing a window of his property. He thus exposed for eight hours. This format a blurred image - but now well known - a building, a tree and a barn.
Wanting to refine his method Niepce joined in 1829, a dynamic entrepreneur named Louis Jacques Mande Daguerre (1787-1851). Beginning in 1829, Daguerre began his real work in chemistry by using iodine discovered by Bernard Courtois. Jacques Daguerre has made significant progress in the years following the death of Niepce, occurred in 1833. The vapors of iodine are used as a sensitizer on a copper plate covered with a layer of polished silver. The reaction between iodine and silver product of silver iodide, a substance which proved to be more sensitive to light than the asphalt. By chance, he discovered that if a plaque was presented, was treated with mercury vapor, the latent image appear clearly.
From that time, the exposure time is reduced considerably. Later, Daguerre was aware that dipping the plate in a salt solution it could prevent the image is black with time.
Arago this discovery to the Academy of Sciences in 1839 Daguerre and the markets as "daguerreotype." The State acquires french against an annuity and then made "gift to the world."
But all these images could not be produced in a single copy at a time, their quality was uncertain, and requires exposure times of several tens of minutes, making it very difficult to portraits.
In 1839, when Daguerre's invention - the daguerreotype - was presented to the public, it received considerable acclaim. In his History of Photography, the specialist Helmut Gernsheim said: "It is probable that no invention has so exalted the public imagination and has conquered the world at speeds as fast as the Daguerreotype. A witness says: "An hour later, all the shops were taken over. But it was not possible to collect enough instruments to meet the tide of daguerréotypeurs budding. A few days later, we could see all the places in Paris, facing the churches and palaces, darkrooms mounted on the tripod. All physicists, chemists and intellectuals of the capital polissaient silver plates. Even prosperous grocers could not refuse the pleasure to sacrifice some of their resources on the altar of progress, leaving volatilise with iodine and melt in the mercury vapor. "
The Parisian press was quick to name this mode of "daguerreotypomanie. Faced with the remarkable quality of daguerreotypes, Sir John Frederick William Herschel, a British scientist says: "It is no exaggeration to describe as miraculous." Honore de Balzac, Theophile Gautier and Gerard de Nerval and have been traditionally described as the invention of magic. However, not everyone has welcomed this invention. In 1856, the King of Naples has banned photography, perhaps because it was believed linked to the evil eye.
Moreover, seeing the daguerreotype, the painter Paul Delaroche exclaimed: "From today, painting is dead! The invention has caused great concern among the painters who have perceived as a threat to their livelihood. One commentator said another of their fears by saying: "The photograph is so strictly faithful to the end, it actually threatens to destroy the concept that everyone is of beauty." In addition, photographic images have been criticized for their relentless realism that has shattered the illusions of beauty and youth that will be rocked before.
The invention of the negative
William Henry Fox Talbot (1800-1877) conducting parallel research to those of Niepce and Daguerre from 1833 and is convinced he invented photography. In 1840, he invented the "calotype" positive-negative process that allows the dissemination of multiple images. Follow other research that gradually improve the image quality, sensitivity to light sensitive surface and to simplify the procedure for shooting: 1847 "conducted albumin (Claude Felix Abel Niepce de Saint-Victor, Nicephore cousin), 1850 "wet collodion process" and 1851 "ambrotype (Frederick Scott Archer), 1852" tintype "(Adolphe-Alexandre Martin). We must not forget the work negative / positive paper Hypolite Bayard, french photographer (contemporary Fox Talbot), who in 1839 published the first self-portrait (the drowning-suicide). Niepce, Daguerre and Talbot were not the only ones to claim authorship of the photograph. After the announcement of Daguerre in 1839, at least 24 men, from Norway to Brazil, did the same.