Teaching Grannie to suck eggs, part 47: you don't need the viewpoint of the subjective camera to know that all cinema is voyeuristic. We look into others' lives and get our kicks from their pain, pleasure and fear. Call it escapism.

This is so obvious, it barely needs stating. So it's always a shock when critics complain that a particular film is voyeuristic. Well, all films are, though, admittedly, few go quite as far as Michael Powell's 1960 classic, Peeping Tom, which has films within films within films - including a snuff movie - and makes you see life through the eyes of a serial killer (Carl Bohm). That's what the critics who originally called the picture 'disgusting' and 'revolting' were truly objecting to: not the subject matter, but Powell pointing out that audiences ritually - indeed, routinely - participated in everything from joy to love to rape to sex killings.

Powell rubbed everyone's genteel noses in the dirt - implicated them, so to speak - and saw his career crumble. Yet the very same year Hitchcock produced Psycho, which not only had Anthony Perkins spying on Janet Leigh as she undressed (remember that huge close-up of his eye?) but actually put us in the position of stabbing a naked woman to death in a shower. Psycho was the biggest hit of a distinguished career, perhaps because Hitchcock, unlike Powell, used 'entertainment' to cloak his dark intentions. Psycho, he said, was 'just my little joke' - Hitchcock was the naughty fat boy who literally got away with the dirty look. Powell, on the other hand, discovered the cost of being caught peeking . . .

'Peeping Tom' is at the Camden Plaza (071-485 2443)