HISTORY OF PHOTOGRAPHY

Photography (Greek "drawing with light" from photos = light, and graphis = stylus, paintbrush or graphê = representation by means of lines, drawing) is the technique of recording, by chemical or mechanical means, a everlasting image on a layer of material sensitive to light exposure.The first photograph is well thought-out to be an image produced in 1825 by Nicéphore Niepce on a polished pewter plate covered with a petroleum derivative called bitumen of Judea. It was produced with a camera, and required an eight hour exposure in bright sunshine. In 1839 Jacques Daguerre developed a process using silver on a copper plate called the Daguerreotype. Almost at the same time, William Fox Talbot developed a different process called the calotype, using paper sheets covered with silver chloride. This process is much closer to the photographic process in use nowadays, as it produces a negative image that can be reused to produce several positive prints. Hippolyte Bayard also developed a method of photography, but delayed announcing it and so was not recognized as its inventor.

The Daguerreo type proved more popular as it responded to the demand for portraiture emerging from the middle classes during the Industrial Revolution. This demand, that could not be met in volume and in cost by oil painting, may well have been the push for the development of photography. Neither of the techniques involved, the camera obscura, and the photo sensitivity of silver salts, were 19th century discoveries. Camera obscura were used by artists in the 16th century, as an aid to sketches for paintings, and the photo-sensitivity of a silver nitrate solution was observed by Johann Schultze in 1724.