The camera never lies. But it doesn't understand what it sees

A phrase jumped into being in the early Sixties, cinéma-vérité, that took on the moral force of a political slogan. What the label and its approach seemed to promise was an unequivocal record of events. The thrust was journalistic originally, but it took on ideological tones with the thought that all the brave cameraman needed to do was film compromising events, and then show them to the public. How could there then be any result except revelation, enlightenment and fresh political processes free from compromise?

A phrase jumped into being in the early Sixties, cinéma-vérité, that took on the moral force of a political slogan. What the label and its approach seemed to promise was an unequivocal record of events. The thrust was journalistic originally, but it took on ideological tones with the thought that all the brave cameraman needed to do was film compromising events, and then show them to the public. How could there then be any result except revelation, enlightenment and fresh political processes free from compromise?

Cinéma-vérité was made possible by new lightweight cameras and tape recorders that could get into the fiercest action, or smoke-filled rooms, without being obtrusive or ponderous. And if the camera had recorded something, why, it must have happened. Hadn't Jean-Luc Godard announced that the cinema was the truth 24 times a second? (In which case, is there more truth in slow motion – 72 frames per second?) There was a great rush to make films in which dumb cameras allegedly made art and history by sitting in corners recording all that happened. There was an onlooker in Deeley Plaza, Dallas, on 23 November, 1963 – Abraham Zapruder. He shot the president being driven by on 8mm ... he shot the president being shot. Anyone could see Mr Kennedy jerk back, as if shot from the direction of the grassy knoll. Hence, conspiracy flowered – until anatomical experts said, no, that motion was a nervous reaction to a bullet fired from the rear. The camera may not lie, but it doesn't understand what it sees.

The mood of those heady days, and the fierce arguments over truth, may be joined again, in Edinburgh later today, as Haskell Wexler appears at the festival. He is there to show his 1968 cinéma-vérité classic, Medium Cool, along with a documentary on the making of it, nicely titled Look Out Haskell, It's Real, made by Paul Cronin.

Haskell Wexler, who is 75 this year, is a unique figure. He is, most immediately, a brilliant, versatile cinematographer, hugely resourceful, capable of working in many moods and styles, and a bonus to any director capable of getting him interested in a project. As such, Wexler has won two Oscars for cinematography – for the abrasive black-and-white of Who's Afraid of Virginia Woolf and the sun-blanched views of the West from Bound for Glory, Hal Ashby's biopic of folk-singer Woody Guthrie. He also photographed the original Thomas Crown Affair, In the Heat of the Night, Coming Home, Richard Pryor: Live on the Sunset Strip, and John Sayles' Matewan.

He is at the same time a hero of the left, a friend to the oppressed everywhere, and a movie-maker with faith in the power of reportage to shame police and governments, and to make leaders abandon cruel and corrupt practices. So, another part of his life has been given to political documentary: The Bus, about civil rights workers going to Washington; Brazil: A Report on Torture (1971); Introduction to the Enemy (1974), which accompanied Jane Fonda on her controversial visit to Hanoi; Underground, about a range of secret political resistance movements in America; and Medium Cool, which he wrote and directed and co-produced.

You might gather from Haskell's dual careers as photographer and activist that he has felt that split in life where the cameraman (if he is a decent human being) wonders whether he should abandon the camera and help the wounded person he is filming. That is what Medium Cool explores in a story about a TV news cameraman (played by Robert Forster) whose own life circumstances run over into the tumult of the 1968 Democratic Convention in Chicago.

In my opinion, Medium Cool has not lasted well – that's true of many phenomena (and films) of the late Sixties. The human story is a little naïve and its overlap with real, dangerous events is contrived, even if you can often feel the peril on the screen. When it comes to cinéma-vérité, I prefer the work of Richard Leacock, Jean Rouch and even that deadpan scenarist of the boring, Andy Warhol. But anyone is going to be enthralled by hearing Wexler talk and intrigued by that aspect of the late Sixties when hardly anything happened without it being filmed. Indeed, there were once or twice film crews filming the film crews filming the real thing.

That's comic and ridiculous. What is close to criminal, however, is the way television news reporting has since drawn back from difficult, live coverage of events. The people who do not want to be seen or photographed – the world's political leaders – as they decide our fate, have done a terrific job in excluding cameras. But they have been horribly assisted by the new feebleness of the media. And Haskell Wexler stands proud as an example of the dangerous way to work.

d.thomson@independent.co.uk

'Look Out Haskell, It's Real!' and 'Medium Cool': Lumiere, Edinburgh (0131 623 8030), 2pm and 4pm today