The history of photography began in remote antiquity with the discovery of two critical principles: camera obscura image projection and the observation that some substances are visibly altered by exposure to light. There are no artifacts or descriptions that indicate any attempt to capture images with light sensitive materials prior to the 18th century. Around 1717 Johann Heinrich Schulze captured cut-out letters on a bottle of a light-sensitive slurry, but he apparently never thought of making the results durable. Around 1800 Thomas Wedgwood made the first reliably documented, although unsuccessful attempt at capturing camera images in permanent form.
In the mid-1820s, Nicéphore Niépce first managed to fix an image that was captured with a camera, but at least eight hours or even several days of exposure in the camera were required and the earliest results were very crude. Niépce's associate Louis Daguerre went on to develop the daguerreotype process, the first publicly announced and commercially viable photographic process. The daguerreotype required only minutes of exposure in the camera, and produced clear, finely detailed results. The details were introduced to the world in 1839, a date generally accepted as the birth year of practical photography.
The oldest surviving photograph of the image formed in a camera was created by Niépce in 1826 or 1827. It was made on a polished sheet of pewter and the light-sensitive substance was a thin coating of bitumen, a naturally occurring petroleum tar, which was dissolved in lavender oil, applied to the surface of the pewter and allowed to dry before use.
Niépce died suddenly in 1833, leaving his notes to Daguerre who experimented with photographing camera images directly onto a mirror-like silver-surfaced plate that had been fumed with iodine vapor, which reacted with the silver to form a coating of silver iodide.
The daguerreotype proved popular in response to the demand for portraiture that emerged from the middle classes during the Industrial Revolution. This demand, which could not be met in volume and in cost by oil painting, added to the push for the development of photography.
Roger Fenton and Philip Henry Delamotte helped popularize the new way of recording events, the first by his Crimean War pictures, the second by his record of the disassembly and reconstruction of The Crystal Palace in London. Other mid-nineteenth-century photographers established the medium as a more precise means than engraving or lithography of making a record of landscapes and architecture: for example, Robert Macpherson's broad range of photographs of Rome, the interior of the Vatican, and the surrounding countryside became a sophisticated tourist's visual record of his own travels.
In 1839, François Arago reported the invention of photography to stunned listeners by displaying the first photo taken in Egypt; that of Ras El Tin Palace.
Ultimately, the photographic process came about from a series of refinements and improvements in the first 20 years. In 1884 George Eastman, of Rochester, New York, developed dry gel on paper, or film, to replace the photographic plate so that a photographer no longer needed to carry boxes of plates and toxic chemicals around. In July 1888 Eastman's Kodak camera went on the market with the slogan "You press the button, we do the rest". Now anyone could take a photograph and leave the complex parts of the process to others, and photography became available for the mass-market in 1901 with the introduction of the Kodak Brownie.
(Wikipedia)