Visualisation - or, 'The Picture In Your Head'

The Picture In Your Head.

What do we mean by Visualisation?

Visualisation is a process whereby the photographer considers the scene they wish to photograph and makes a series of decisions about the equipment, techniques and post-production processes available to them, in order to translate the “picture in their head” into the final produced image. The process will involve consideration of all things practical, technical, aesthetic, possibly even financial, which will have a bearing on the production of the final image.

Finding an appropriate viewpoint, anticipating the appropriate light, selecting a lens and composition ... these are all elements within the process of visualisation

The following considerations may be included in the process.

Aesthetic:

•Why is the photograph being taken? What is its ultimate purpose or use?

•Which objects, or areas of the photograph, does the photographer desire to be sharp?

•What overall framing and composition of the scene is desired?

•What is the most appropriate lighting for the subject matter?

Technical:

•Which techniques are required to produce the desired image sharpness?

•Will the prevailing weather conditions have an influence on those techniques?

•What equipment constraints are there?

Practical:

•Is the ideal viewpoint physically attainable, or are there compromises necessary?

•Is this the appropriate time of day/time of year?

Why is visualisation useful?

Many keen but unfocussed (no pun intended) photographers are frustrated by the inconsistency, and apparent unrepeatability, of their best work. Visualisation is a process which encourages a more systematic approach to one’s photographic practice, which will ultimately help the photographer to take control of the techniques which affect the photographic image. This will improve both the quality of their images, and the consistency - the good photographs will therefore become intentional, for known and understood reasons, rather than bafflingly accidental.

How do we see?

In simple terms, when a scene is scanned by the eye, light from the part of the scene currently being scanned is focussed by the eye onto the retina, and the signal from the retina is transmitted to the brain where it is translated into a visual picture that the viewer can make sense of. As the eye moves over the scene, taking in objects that are close by, and objects that are far away, the eye constantly refocusses the image it is receiving, and the brain constantly reprocesses the information it is receiving. Even in conditions of near-darkness the eye can distinguish enough detail to allow the viewer to avoid obstacles, because the brain is able to interpolate imprecise data and fill in the gaps from previous experience.

How does a camera’s way of “seeing” differ from the eye’s way of seeing?

The eye is often compared with a camera, and there are some similarities. Both use a lens to focus light, both use a light-sensitive medium to record the impression of the light, but there the similarities end. Aside from the obvious difference of the eye seeing a constantly changing and moving image, the two principal differences between the eye and the camera that are of significance to the photographer, are the ability of the eye to constantly refocus, and the ability of the eye to see (via the brain’s interpretive abilities) in a very wide range of light conditions. The ability of the eye to rapidly change focus, and thus for nearby objects to be perceived in sharp focus virtually simultaneously with more distant objects, is not shared by the camera. The camera lens may be focussed on only one plane at a time; therefore in a photograph, only objects lying on this plane will be measurably sharply focussed. In practice, there are photographs which appear to be sharp throughout the depth of the scene, so there is a technique which allows the photographer to mimic this ability of the eye.

The ability of the eye to see detail in a much wider range of light conditions than can a light- sensitive emulsion or digital sensor, though, is one which poses many more problems for the photographer. Generally speaking, the brightness range (scene contrast) able to be perceived by the eye/brain combination can be as much as 10,000:1 - that is to say, the brightest part of the scene can be 10,000 times brighter than the darkest, and the eye can still distinguish detail. In the case of a colour negative film, this contrast range is reduced to around 1000:1, and in the case of a transparency film, it is reduced to around 100:1. Combine that with the contrast reduction involved in producing a paper print of a photograph and it should be evident that a photographic representation of the real world is not equivalent to literal reality. Quite the contrary, in fact - a  photograph, by its very nature, is always at best an interpretation of reality, and the person in control of that interpretation is, of course, the photographer. However, until the photographer makes full use of the process of visualisation, and incorporates into that process some measure of the shortcomings of the way a photograph represents the real world, then ultimate control of the image will remain elusive.

For futher in-depth discussion of the differences between the eye/brain system and the camera/film or camera/sensor systems, see the following articles on my other Blog:


Opening Gambit - Decisive Moment v. Saccadian Rhythm


"Size Constancy Scaling"