Part four - Reality and intevention

Project - digital photography and 'truth'

As seen at the beginning of this course, one of the revolutions wrought by digital photography has been that the photographer is responsible for everything to do with the image, from capture right up to producing the finished image. In particular, the recording of images as digital files means that full access is gained to every pixel. Unlike film photography, in which at some point the image becomes physically locked into the emulsion, a digital image is at all times available for adjustment.

This raises an issue that was never before particularly significant - the alteration of meaning and content. When digital photography began to be used professionally for publication, many people voiced concerns about the threat of what was perceived to be the inherent 'truth' of a photograph. How were we to know any more that a photograph was truly taken from life, and not in some way manipulated unscrupulously?

There has indeed been a number of publicised instances of deliberate and effective fakery. Most of these have been in the form of additions and deletions, painstakingly retouched, in order to make the picture more effective, more as the photographer wanted it to be. Usually these were commercial in motive, to make the picture more saleable, more likely to be used by a magazine or newspaper. And for every instance uncovered because of someone else's investigation, it is fair to assume that more go undetected.

This does not, of course, suddenly invalidate documentary photography with a sweep. But it does make all of us that bit more aware of what might happen. And while concocting a false photograph is clearly dishonest, and something that almost all photographers would claim never to do themselves, the reality of digital processing means that there are no clear dividing lines between what is acceptable and what is not. This may come as a surprise to many people who considered that practical details of digital processing, and who believe that the matter is exclusively ethical. In this part of the course it will be demonstrated that there is a continuum of image adjustment in digital photography, from the basic necessities of preparing a digital camera file so that it can be viewed optimally, to the extremes of alteration and fake. Bon Gilka, former director of photography at the National Geographic magazine, expressed the professionals' view of the extreme when he said that manipulating images is 'like limited nuclear warfare. There ain't none'.

Yet the series of projects here will enable a photographer to work through the continuum in order to experience the shades of intervention and to decide for yourself which aspects of image work on the computer are acceptable or unacceptable according to the situation. An ethical position is certainly called for, but given the responsibility for processing the images, simple positions of outright dismissal or blanket acceptance are untenable.

At the lowest level of intervention, digital files fresh from the camera need to be processed in order to prepare them for display on a website or for printing. At its most basic, this is largely a technical matter, with no significant interpretation,. The fundamental image qualities are:

• overall brightness
• overall contrast
• density or 'blackness' of the darkest tone
• density or 'whiteness' of the lightest tone
• overall colour cast - white balance

The principle of optimising these, of getting then 'right', implies that there are common standards, that there are norms for reproducing images. At this end of the continuum of digital adjustment no-one would seriously argue otherwise. The raw file is, as tome people like to call it, a kind of digital negative, in the way that film photography a negative is an intermediate stage between capture and display.

This concept of correctness, of generally accepted standards for tone and colour, is worth reflecting on. The reason for this is that at some point in processing, interpretation is called for, and the result begins to depart from 'standard'.

The previous section of this course, part three, looked at optimising an image and shooting in raw to capture maximum information. These are the most basic and uncontentious forms of correction. In the next part of the course I will address another widely-accepted reason for correction - blemishes. When using a digital SLR, an inevitable form of blemish is dust in the sensor, changing lenses allows dust and other particles into the camera's mirror box, and they usually end up on the surface of the sensor. Another kind of blemish that suggests correction is lens flare, particularly the kind that shows as a string of bright polygons.