History and development

Abstract

The principles of photography go back into history much further than most people would appreciate. The ability of light to form images was well known to scholars as long ago as the fourth century BC. The Greek philosopher Aristotle was the first person to comment on the practical use of this phenomenon in the study of astronomy. By using a darkened room and allowing the light to pass through a small hole, an image of the sun was created on the opposite wall. He had also noticed that the size of aperture through which the light passed had a direct effect on image sharpness. Some 1300 years later, Hassan ibn Hassan, a tenth century Arabian scholar, wrote an account of a solar eclipse in which he commented on the effect of different size holes, the smaller the hole the sharper the image. By the thirteenth century Roger Bacon was familiar with the ability of light to form images of scenes, as well as being used to observe solar activity. The term ‘camera obscura’ comes from the Latin and means dark room, and that is exactly what the first examples were, and as such their application was limiting. The first known published reference to one appeared in 1544. Several fixed camera obscuras exist around the world; now mainly tourist attractions they do afford the visitor an idea of the basic principles of photography (see Figure 1.1). In Britain there are three open to the public, one in Bristol, one in Edinburgh and one at Builth Wells in Wales (see Figures 1.2 and 1.3). In the original camera obscura the image appears upside down and back to front, in later versions where a mirror was introduced the image appeared the right way up but still back to front. With the three existing cameras in Britain a prism is fitted in the lens housing and the image appears the right way round. A seventeenth-century contemporary drawing of a camera obscura. In the seventeenth century this building at Clifton, Bristol, was a snuff mill, the windmill tower was turned into a camera obscura in 1829 and is maintained in working order, one of three in Britain.