From Analogue to Digital

Illustrations used by Professor Martin Lister, author of the final chapter in earlier editions of this publication, to detail the implications of digital photography.

Analogue And Digital

Traditionally, images were analogue in nature. That is, they consisted of physical marks and signs of some kind (whether brush marks, ink rubbed into scored lines, or the silver salts of the photographic print) carried by material surfaces. The marks and signs are virtually inseparable from these surfaces. They are also continuously related to some perceivable features of the object which they represent. The light, for instance, cast across a rough wooden table top becomes an analogous set of tonal differences in the emulsion of the photograph. A digital medium, on the other hand, is not a transcription but a conversion of information. In short, information is lodged as numbers in electronic circuits. It is this feature of digitisation which has meant that images can now exist as electronic data and not as tangible, physical stuff. Some of the key differences can be set out as follows:

Analogue	Digital
transcription: the transfer of one set of physical properties into another, analogous, set	conversion: physical properties symbolised by an arbitrary numerical code
continuous: representation occurs through variations in a continuou field of tone, sound, etc.	unitised: qualities divided into discrete, measurable and exactly reproducible elements
material inscription: signs inseparable from the surface that carries them	abstract signals: numbers or electronic pulses detachable from material source
medium specific: each analogue medium bounded by its materials and its specific techniques	generic: one binary code for all media, enabling convergence and conversion between them

Digitisation is also the effective precondition for the entry of photographic images into the flow of information which circulates within the contemporary global communications network. It is their translation into a numerical code that now enables them to be electronically transmitted. For the above reasons, questions have arisen about the place of images in time and space, where they can be said to actually exist, about how and where they are stored when in electronic form, how and by whom they can be accessed, used, owned and controlled.

For a full discussion of the analogue/digital distinction see:

Timothy Binkley (1993) ‘Refiguring Culture’ in P. Hayward and T. Wollen (eds) Future Visions: New Technologies of the Screen, London: BFI.

A-M. Willis (1990) ‘Digitisation and The Living Death of Photography’ in P. Hayward (ed.) Culture, Technology and Creativity in the Late Twentieth Century, London: John Libbey and Co Ltd.

Digitising Photographs: The Initial Implications

• A shift in the location of photographic production: from the chemical darkroom to the ‘electronic darkroom’ of the computer.
• The outputting of single photographic originals in an expanded range of ways, from ‘hard copy’ through transparencies and varying forms of print, to the computer and TV screen, and websites.
• An unprecedented ease, sophistication and invisibility of enhancing and manipulating photographic images.
• The entry of photographic images into a global information and communications system as they become instantaneously transmissible in the form of electronic pulses passing along telephone lines and via satellite links.
• The high-speed transmission of news images which are no longer containable within territorial and political boundaries.
• The conversion of existing photographs and historical archives into digital storage banks which can be accessed at the screens of remote computer terminals.
• The potential of the new information and image networks for greatly extending the practices of military and civil surveillance.
• The unprecedented convergence of the still photographic image with previously distinct media: digital audio, video, graphics, animation and other kinds of data in new forms of interactive multimedia.