Seb Grant steps out on Paths to Fame: Turner Watercolours at the Courtauld: Watercolour is to oil-painting what rounders is to cricket. OK, probably not, but the texture, richness and sense of permanence of a good oil painting, frequently feels more satisfactory than the subtleties of a water-colour. Or so I thought. But my prejudices were confounded recently at an exhibition of J.M.W Turner's watercolours at the Courtauld Gallery (until 25 January).

The exhibition spans Turner's career from precocious 16 year-old teenager to artistic statesman -- and this linear tour de force of the artist's burgeoning talent is an absolute delight. The Courtauld's own works have been supplemented by loans from Tate and private collections -- and the overall effect is a gradual unveiling of Turner's astounding artistic path to maturity.

A few weeks earlier I'd been humbled by two extraordinary Turner canvasses at New York's Frick Collection, Antwerp: Van Goyen Looking Out for a Subject, 1833, and Cologne: The Arrival of a Packet-Boat: Evening, 1826. These two masterpieces utterly dazzle the viewer and their appeal is almost cinematic.

Turner's watercolours have a different appeal. They share the other-worldliness of his oils and yet there is greater sense of mystery, even sadness. Perhaps the stand-out work is Dawn After the Wreck -- a rather affecting picture of a lone dog howling by the sea. It evokes a sense of loss, loneliness and tragedy, appealing to the visitor to attach their own narrative to the scene. I found myself staring at this watercolour for far longer than I spent in front of the Frick's magnificent Turner oils.

The Courtauld have produced short films about seven of the paintings and the show's curator, Joanna Selborne gamely tackles the am-I-a-curator or am-I-a-TV-presenter dilemma. The videos are straightforward and efficient -- but permit me one gripe. I just wish the artworks had been filmed properly, as opposed to included with rather abrupt captures, presumably from transparencies.

It wouldn't be an Illuminations blog without a shameless plug for our films so allow me to offer, Turner at Tate or Turner and Venice, from which the image above comes. Please purchase either one. Our alternative business plan is to hijack very large ships off the Somalian coast.

Detail of From Here to Eternity (blue), 2008, by Susan Hiller

Ed Wright wrestles with the ideas and images of Susan Hiller at Timothy Taylor Gallery: Proposals and Demonstrations (until December 20) is a show of new work by artist Susan Hiller. Hiller is one of the many artists featured in State of the Art, Illuminations’ documentary series made in the mid-1980s for Channel 4.

In episode 3 of State of the Art Hiller contends, 'Art functions as a mirror to show people, including the artist, what they don’t know they know.' This concept expresses itself in Hiller’s work through an exploration of the irrational: the subconscious, the dream world and the paranormal. Her work aims to suspend rational thought. Would it prove so today at the Timothy Taylor Gallery? I took a look at some of the art on display.

Homage to Yves Klein, 2005-07, plays on the idea of levitation, which Hiller identifies as one of the 'mystical or spiritual traditions derided as superstitious by scientific rationalism'. The piece is a montage of photographs that purport to show people levitating, presumably using some kind of psychic ability. However, as Hiller acknowledges, the photographs are all faked, as indeed was the original Yves Klein photograph that inspired the work. It’s slightly difficult to know what to conclude here, so I chalk one up for scientific rationalism.

The three From Here to Eternity, 2008, projections each display a coloured dot -- red, blue, or green -- navigating its way through a labyrinthine pattern projected on to the wall. They invite you to contemplate ideas of pilgrimage and spirituality, as you watch the dot inexorably work its way to the centre of the maze. One can also see this, of course, as symbolic of 'the obstacles and misunderstandings on the hard road of life'.

I liked this idea a great deal and sat for some time eagerly awaiting one of the dots to finally reach the centre. The blue dot moved ever closer and I waited to see what the conclusion of its long, hard journey would reveal. The dot reached the centre, paused -- and then retraced its steps back the way it had come! This left me feeling very desolate.

Probably the standout piece in the exhibition is called Magic Lantern, 1987. The viewer is confronted with a changing projection of red, yellow and blue circles while wearing headphones that play the results of an experiment in which a Latvian scientist, Konstantin Raudive, claimed to have recorded the voices of the dead. (The audio is available from ubuweb here.)

The commentator, a woman’s voice characterised by that archaic Received Pronunciation of the first British broadcasters, translates these spectral voices amid the overwhelming whir of static interference. In the darkened room with headphones on and only the stark projections for company this was truly disconcerting. Well, it was until Winston Churchill chipped in. He was saying his own name over and over again.

PS: Psi Girls, 1999, a 5-screen video installation by Susan Hiller is currently on show in the collections galleries at Tate Modern.