Much of the post processing we do to images cannot be seen as simply as some additional thing that is done after the fact to alter images for our own ends. It is not the case that the camera has produced an ‘objective’ representation of reality that we then manipulate to somehow falsify that representation.
We established in the first part that what the camera has recorded is the photographer’s interpretation of the world around him and that various choices of equipment that he has made have led to the production of an image that is a product of a particular way of seeing the world, and that therein lies part of the photographer’s art.
Post processing is something that is done hand in hand with the capture of the image itself, to accompany and accommodate the particular abilities and deficiencies of the equipment involved in the capture process. It is the combination of the capture and the post processing that creates the final image.
Digital cameras are very powerful yet flawed devices. They can capture only slightly more than half the dynamic range that our eyes see in a scene. If the light is poor, exposures are long, or high ISO settings are used then digital noise is generated. Their sensors are normally covered with an anti-aliasing filter to combat moire patterns but this distinctly softens the image. All but the most expensive professional lenses have significant flaws, with various types of distortion, chromatic aberration and vignetting. At small apertures they soften the image due to diffraction. A great deal of what happens in post processing is simply correction of these problems.
On many occasions I have seen solemn declarations on photographer’s sites that they do not manipulate their images in any way, and this information is sometimes presented as a selling point for their photography. However, what is being declared here is not, and can never be, true.
There are various possibilities here.
1) The photographer shoots with film. The problem here is that every film has different characteristics. This is the selling point for particular films. In my own field the most celebrated film is Fuji Velvia 50, lauded for its rich colours and saturated greens and reds, colours that almost never occur in nature. The very act of choosing a film for a shot is an interpretation of reality. Many film photographers shoot black and white film, which looks great, but certainly bears little resemblance to the world as we see it.
2) The photographer shoots JPEG files. Here the camera does the RAW conversion without human intervention. Or does it? Most cameras have settings for sharpness, contrast and colour saturation in their JPEG files. It is not simply the case that if you leave these settings unaltered at their defaults then you have some greater claim to an ‘objective capture’ because the manufacturer has chosen the default settings for that particular camera (and the reality is usually that the manufacturer thinks that consumers like super saturated slightly overexposed images and dials these default settings in accordingly). Each camera has its unique JPEG processing characteristics, much discussed in reviews, and the very act of choosing a camera for a shot is an interpretation of reality, and even more so if you make changes to its JPEG settings.
3) The photographer shoots RAW. Here I find it very hard to make any sense of a claim not to manipulate images. RAW files are, roughly speaking, the digital equivalent of negatives. They are flat, often drab in colour, have flexible white balancing, often either lack white and black points or clip them, lack contrast, are not sharpened and contain varying amounts of noise. If the claim is that the photographer has merely processed the RAW file at its default settings then I find this very hard to believe, but this is irrelevant anyway, because every RAW convertor has its own characteristics and processes files differently. The very act of choosing a RAW convertor for a shot is an interpretation of reality, and even more so if you make changes to its settings.
There is simply no escaping the fact that whether film or digital, edited or unedited, a photograph is an interpretation of reality, and not an objective representation of it.
I will consider the more ‘creative’ application of a RAW convertor or the manipulation of a scanned film image, JPEG file or processed RAW file in Photoshop, or some other bitmap editor, in the third part of this article.
Before winding up here though, it is worth considering what happens to the image at the end of any process. If it is not to languish on your hard drive then it will be either viewed on your computer, prepared for the web, or printed out. Here we come up against the issue of colour gamuts. Your image file will likely contain far more information than can be viewed on a computer screen or printed out. Moreover, computer screens vary wildly in the number of colours they can display, as do inks and papers. Yet again the image has to be manipulated to fit the medium, a process of interpretation, and one that invariably involves throwing away data in the image file, further distancing the image from any notion that it is an objective representation of reality.