The Visual Issue - An Investigation into the Techniques and Methodology used in Windfarm Computer Visualisations

Selected Extract

The problem with the Windfarm Industry's visuals.

There is no way that a camera can truly replicate what we see. We view stereoscopically for a start and have the ability to see in three dimensions, whereas a photograph is monoscopic in nature and devoid of any distance information. But by a careful choice of lenses along with other factors, we can achieve a reasonable approximation.

Whilst a 50mm lens is called a standard lens because it generally represents what we see within our main area of visual awareness, the choice of lenses for Visual Impact Assessment purposes requires much more careful consideration.

For any planning application, it is essential to provide the viewer with sufficient visual information so he can form a realistic sense of size and scale of the proposed development. The choice of lens to form a photographic backdrop for a photo-montage really depends on the subject matter and the number of known references contained within the photographic frame. By known references, we mean things that we see every day of a ‘known scale' i.e. buildings, vehicles, people etc. So in an urban setting where there may be many such references, the scale of a development can easily be assessed even if a wider angle lens is used. In other words, we use our own brain to form a sense of scale.

In a landscape context, the situation can be very different. Photomontages of turbines are often shown on bare hillsides at a considerable distance with no features or known scale references. Because we are now looking at an image on a flat plane, we have no real idea of true distance for the reasons explained by the Center for Visual Sciences. Whilst we know by everyday experience the approximate height of a two storey house and can therefore reasonably gauge its distance within a landscape, it is different for wind turbines. There are no identifiable scale references because of their simple shape and form. So when we view an image, we simply do not know if the turbines are 100ft high, 200ft high or even 400ft high. We simply have no means of visually scaling them in our own brain.

We therefore have to rely on an impression of distance to give us a sense of scale, and this can only be achieved by using the focal length of a camera lens. The wider the angle of view of a camera lens, the further away an object appears, the narrower the angle of view, the nearer an object appears. The basic science of photography since the camera was invented.

Quite simply, when we stand at a particular viewpoint........will the turbines look this near?.......................this near?....................................or this near?

With further research using computer analysis, we discovered that the developers' photomontages, as interpreted by the public, actually reduced the real visual impact by up to a factor of three, with certain applications exceeding this.