Banksy

The first thing Banksy does in the only film he has directed is tell us it is not about him. He sits under a hood with his voice put through a distorter and explains that a Frenchman spent years filming him, and that the footage turned out to be about the Frenchman. Then he shows us that footage. It is the same move he makes on a wall: point at one thing, paint another, and let whoever is looking work out which one they were meant to see.

Exit Through the Gift Shop (2010) is his sole feature, and it is made mostly out of somebody else's material. Thierry Guetta, the Frenchman, shot more than 10,000 hours of street artists at work at night, and the editor Chris King cut that down to 86 minutes that never drag. Banksy's own account of the process is that he "spent a year watching footage of sweaty vandals falling off ladders." Rhys Ifans narrates in a flat Welsh murmur and refuses to oversell anything, and Geoff Barrow's music gives the night shoots the pulse of a heist. Shepard Fairey is there too, and the film is at its most straightforwardly enjoyable when it is simply watching people put things up.

What Banksy is good at, on screen as on brick, is the price tag. Steve Lazarides describing what the work began to fetch tells you more about the market than a lecture would. The second half, in which Guetta puts down the camera and tries making art himself, is where the film stops being a history and becomes a test of everyone in it. We laughed at his first efforts, and then, hearing him talk about them with total sincerity, felt ashamed of laughing, because he is plainly not in on any joke and the film goes on rolling. Nobody on screen tells him to stop. That discomfort is the best thing Banksy has put in front of a camera.

The weakness is the same as the strength. The joke lands on the collectors, on the press and on Guetta, and never once on the man in the hood, who set the whole thing going and cut it from a safe distance. Whether Guetta is a plant has been argued since the first screenings, and the film is happier with the argument than we were; either answer leaves Banksy looking clever. He is guarded to a fault, embarrassed by his own fame and unwilling to say anything that might cost him, so the film has a great deal of wit and not much feeling. And its history of street art begins, roughly, when Fairey and Banksy did, as if the walls had been blank before.

He has made nothing since and gone back to the walls, where the trick works best: one image, one passer-by, no queue. If he directs again, we would ask him to keep the joke and, for once, stand somewhere it might hit him.