A derivative of the Greek words, photos (light) and graphein (to draw), although some may argue that the word photography is also associated with the Greek word for writing, was born the word PHOTOGRAPHY. First to make the word known globally was Sir John Herschel in 1839.
The essence of photography is the method of recording images by the action of light, or related radiation, on a sensitive material.
There are two distinct scientific processes that combine to make photography possible...............
Optical and Chemical.
Optical.
The Camera Obscura (Latin for Dark room) was a dark box or room with a hole in one end. If the hole was small enough, an inverted image would be seen on the opposite wall. Such a principle was known by thinkers as early as Aristotle (c. 300 BC). It is said that Roger Bacon invented the camera obscura just before the year 1300, but this has never been accepted by scholars; more plausible is the claim that he used one to observe solar eclipses. In fact, the Arabian scholar Hassan ibn Hassan (also known as Ibn al Haitam), in the 10th century, described what can be called a camera obscura in his writings; manuscripts of his observations are to be found in the India Office Library in London.
In the mid sixteenth century Giovanni Battista della Porta (1538-1615) published what is believed to be the first account of the possibilities as an aid to drawing. It is said that he made a huge "camera" in which he seated his guests, having arranged for a group of actors to perform outside so that the visitors could observe the images on the wall.
Roger Bacon’s name is also associated with the development of the lens, some have claimed that it was he who invented spectacles.
Gerolomo Cardano (1501- 1576), an Italian mathematician, introduced a glass disc in place of a pinhole in his camera, and Barbaro also used a convex lens. Why the name lens? It is claimed that because Italian lenses were by-convex, they seemed to resemble the brown lentils they used to make soup - so the lens came from the Latin for lentil.
Chemical.
For hundreds of years before photography was invented, people had been aware, for example, that some colours are bleached in the sun, but they had made little distinction between heat, air and light.
In the sixteen hundreds Robert Boyle, a founder of the Royal Society, had reported that silver chloride turned dark under exposure, but he appeared to believe that it was caused by exposure to the air, rather than to light.
Angelo Sala, in the early seventeenth century, noticed that powdered nitrate of silver is blackened by the sun.
In 1727 Johann Heinrich Schulze discovered that certain liquids change colour when exposed to light.
At the beginning of the nineteenth century Thomas Wedgwood was conducting experiments; he had successfully captured images, but his silhouettes could not survive, as there was no known method of making the image permanent.