James Turrell At the Yorkshire Sculpture Park, West Bretton, Wakefield, until 3 September
For many years James Turrell's work has been a powerful reminder of the primacy of vision in our understanding of the world. In books his projects are beautiful and intriguing, but they really have to be experienced first-hand.
The installation of three major pieces in the Underground Gallery at the Yorkshire Sculpture Park (YSP) offers a chance to do just this, and to share Turrell's insights into the phenomenon of vision.
Individually the works are powerful, but sequentially they are almost overwhelming, as you go through quite distinct visual experiences. You begin with Gray Day (1997). This calls upon the phenomenon of adaptation by which the eye adjusts to very low levels of light by gradually transferring its focus from the central cones of the retina to the peripheral rods. This process takes, initially, about 10 minutes, but then continues at a slower rate for up to an hour.
In his book, Eye and Brain, the psychologist Richard Gregory writes: 'It might be said that in moving from the centre of the human retina to its periphery we travel back in evolutionary time; from the most highly organised structure to a primitive eye which does no more than detect simple movements of shadows.' This is exactly what happens with Gray Day.
At first you experience almost complete blackness - or, more accurately, you have almost no sense of vision. Then, very slowly, three fields of light become apparent, a central rectangle of purple hue and soft, pale yellow ellipses on either side. Deprived of all familiar visual cues you are compelled to be still. Then, as adaptation takes place, you become more confident. You have travelled through evolutionary time and 'learned to see'.
With the next piece, Ganzfeld (2005), the experience is quite different. You walk on a sloping surface towards a light source at the far end of a space that widens in plan, enveloped in shadowless, vivid-blue light.
In Turrell's words, 'the air in the space seems physically charged with coloured light and to come right up against your eyes'. Turrell suggests that, in Ganzfeld, you sense that the 'imaginative' space extends beyond its architectural confines. By virtue of its extreme uniformity you see the light rather than the space itself.
This is uncanny and moving.
The final work is Wedgework V (1974). Here, back in a setting of low illumination, deep-red light is ordered with such precision that it creates an illusion of actual space - a perceptual inversion of the experience of Ganzfeld. A diagonal plane apparently partitions and layers the visual field, but this is, in reality, a wedge of light not a solid surface. You see, but you are actually deceived.
This absolutely sustains Turrell's declaration that, 'my art deals with light itself, not as the bearer of revelation, but as revelation itself.' These works, seen in sequence, have something of the character of a musical work in three movements. Each acquires further meaning when cast in relation to the others. But perhaps a more appropriate musical analogy is with John Cage's aleatoric pieces, where distinct movements may be re-ordered in performance. It is fascinating, after going from one to two to three, to then revisit the galleries at random.
As you do this you learn yet more about how to see.
An outdoor piece by Turrell in a disused Victorian deer shelter at the YSP will complete next spring. Then, along with the present installation, we can savour more work by this profound artist. But don't wait - go now, and you'll soon have an excuse to go again.
Dean Hawkes is an architect based in Cambridge