Photography is the process of recording images on photographic film or in binary form, based on the principles of optics and chemistry or electronics. The word photography is derived from the Greek words ‘phot-’ meaning ‘light’ and ‘graphein’ meaning ‘to write’.
Photographs are used for identification purposes (passports), providing information (news and discoveries), preserving memories (personal snaps) and for commercial purposes (product advertisements).
Photography in its present form was invented in the early 19th century as a result of advances in optics and chemistry.
A form of primitive photography during the Renaissance employed a device called a ‘camera obscura’, Latin for ‘dark room’. This was a box having a pinhole on the side facing the subject, and an inverted image was projected on a glass screen on the opposite side which would be manually traced by an artist. Soon, it was found that a lens (used instead of the pinhole) could produce even brighter and crisp images.
Frenchman Nicéphore Niépce made the first photograph in the 1820s, after discovering how to copy engravings onto pewter plates using bitumen, a light-sensitive petroleum derivative. He placed a bitumen-coated plate in the primitive camera obscura, and photographed the view from his window with an eight hour exposure. Niépce teamed up with the artist Jacques Daguerre, and they worked together with the aim of making this art of photography more accurate and efficient. The breakthrough occurred in 1835, when Daguerre found out that latent images could be taken with silver iodide, a compound more sensitive to light than bitumen. The image could then be made permanent after washing the plate with salt and warm water.
Daguerre announced this process, called the Daguerreotype, to the French government in 1839, which then announced it to the world, creating great public interest. Daguerre released all rights to the invention of this process and it was made public domain.
Within a month of the French government’s announcement, William Fox Talbot, an English scientist, read an account of Daguerre's invention. Talbot felt greatly disturbed, as it was similar to his own process which he had named photogenic drawing. This was a different process, in which a drawing paper sheet coated with silver chloride would be placed inside the camera obscura, creating a negative image of the subject. The negative would be similarly placed against another sheet, reversing the tones again. However, Talbot found out how to fix the image permanently only about a month later. This process was later renamed calotype, and had the advantage that the same negative could be used repeatedly to produce more positives. Most modern photography relies on a process similar to the calotype.
Colour photography was investigated by scientists throughout the 19th century, although it became popular only after the 1930s. The first successful colour photograph was taken in 1867 by the scientist James Maxwell. National Geographic was one of the first publications to print colour photos. Due to the difficulty involved in taking colour photographs, it did not become popular until 1935, when Kodak introduced the first modern colour film, Kodachrome. Instant colour film was introduced by Polaroid in the 1960s.
Digital photography involves the storage of images digitally, without using photographic film. A digital camera uses a CCD (charge-coupled device), or some other electronic sensor to store the picture. The image can then be copied onto a storage device in a computer, displayed on television screens, or printed out. CCD cameras were first introduced in the market by Sony in 1981, which was named the Sony Mavica. The first true digital camera, DCS 100, was commercially introduced by Kodak in 1990. Soon after this, digital photography began to be used widely in fields such as advertising, graphic design and journalism.