The Photography Handbook
von: Terence Wright
Routledge, 1999
ISBN: 9780203161098
Sprache: Englisch
209 Seiten, Download: 4906 KB
Format: PDF, auch als Online-Lesen
3 The photographic image (p. 68-69)
Technically photography is at the intersection of two distinct procedures; one of a chemical order: the action of light on certain substances; the other of a physical order: the formation of the image through an optical device.
(Barthes, 1982:10)
the painter’s camera obscura is only one of the causes of Photography; the essential one, perhaps, was the chemical discovery.
(ibid: 31)
THE photographic image itself relies upon two essential ingredients: the camera’s projection of an image and the subsequent chemical development of the image. In this context it would be wise to heed the words of the Gestalt psychologists and remember that the whole is more than the sum of the parts, for the medium of photography amounts to much more than the chemical development of a camera image. And this would seem to account for many of the conceptual limitations of the early theorists of photography who had proposed that photography was a form of automated drawing.1 This chapter aims to establish the central characteristics of photography. It aims to answer the following questions:
• What is a photograph?
• Does it tell the truth?
• What information does it transmit?
The instant the shutter of the camera is released, an image is recorded on the lightsensitive surface at the back of the camera. It should be remembered that in normal conditions light is falling onto all objects in the environment, the light is reflected from the surfaces of these objects and bounces around the environment in all directions at an incredibly high speed (186,000 miles per second). It can be described as a complex web of visual information. The camera ‘samples’ an extremely small segment of the light reflected from the environment and by the objects in it, while the camera’s shutter is open with the lens directing and focusing (or projecting) the light onto the back of the camera. As we saw in earlier chapters, the optical principles of the camera have been cited as similar to those of the eye—but that is only as far as it goes.
It is important now to note that this is where the paths diverge between analog and digital cameras. Up to this point, the technical principles of both lens-based systems are essentially the same. The main difference from this point on is in the imprinting, recording, storage and transmission of the image. The analog photograph records the information by means of chemical change on the surface of the film. The pattern of light falling on the film instigates different responses from the silver halides. This initial process is the same with the digital camera as far as the lens projection is concerned. However, in the digital camera a Charged Coupled Device (CCD) ‘translates’ the light’s pattern into a series of digital codes—made up of 0s and 1s. (See Chapter 7 on digital photography.)