It's easy to scoff when artists pick up movie cameras - after all, we've endured the endless, empty-headed meanderings of Andy Warhol's film output and - more recently - had to stomach the film and video scrawlings of just about every Turner Prize nominee of the past decade. Then there's all that experimental stuff from the politicised 60s and 70s - you know: two-and-a-half hours of a camera gradually zooming in on a photo of Trotsky to demonstrate the materiality of the film medium and how it relates to the workers' ongoing struggle against capitalism.

Thank God then, for Surrealism, and the two small films that painter Salvador Dali and poet and wannabe filmmaker Luis Bunuel created together during 1929 and 1930, that brief period when the dream-world of the silent era gave way to the humdrum literal-mindedness of the talkies.