Roots and berries of a modest city shaman's visions

A television colleague of mine, a unicyclist before she became a presenter, once toured West Africa with a troupe of European acrobats and magicians.

They swapped secrets with local magicians, but the Africans would not perform the western tricks without an amulet or charm to transmute the acknowledged sleight of hand into "real" magic. In his richly enjoyable autobiography, John Boorman reveals a lifelong quest for some similar transfiguration of his own powerful conjuring trick, the cinema.

Reconnoitring for The Emerald Forest , Boorman, aged 50, entered the remote Amazon rainforest at a moment when its inhabitants were still in the Stone Age. He tells how he found himself trying to explain his work to the village shaman - no mean task when the nearest cinema is several millennia away. But the tribesman recognised the job description: "You're a shaman, like me." He showed his new accomplice the roots and berries with which he manufactured his dreams and visions. For Boorman, this visit was "one of the great experiences of my life".

What a long way (Boorman's subtext throughout the book) from the constrained semi-detached and semi-despised suburbs of his wartime London boyhood. His account of these early years is remarkable for what features so little in it: the cinema. Not for Boorman the movie seen at age seven hitting him between the eyes and changing his life. For the first quarter of the book, this could be the story of any sort of future adult with a gift for words and insights.

His family had a bungalow by the Thames; his mother was secretly in love with her husband's best friend. To these facts Boorman attributes lifelong compulsions: an affinity with rivers, and the frequent discovery of unintended triangular relationships in both his fictions and his life. He traces an unlikely connection between the stately Thames and the wild Chatooga River, star of his most famous film, Deliverance . He describes a largely happy childhood, but the reader detects an underlying sadness - some kind of anxiety haunting the child himself. The boyhood is watched over by a stiff, unfulfilled father basking in his son's successes but relishing his failures even more.

With so little mention of the cinema, it is something of a surprise when Boorman suddenly lands a job in television. Before long, still in his 20s, he is being offered the running of the BBC's documentary "jewel", Monitor , and afterwards of the new BBC2 (declining both jobs). Here there is a failing in the autobiography. Boorman cannot escape the ingrained modesty that prevents him explaining his rise. We learn almost nothing about how the possessor of exceptional talent experiences the discovery of it. Yet autobiography is scarcely an exercise in modesty. When he dutifully deprecates his "probably flashy" short films, I longed for a paragraph or two from someone else to convey Boorman's early impact. (After I formed this notion, Boorman showed he was there already when, later in the book, he refers to his "hypocritical modesty".) Nonetheless, he conveys a key age in television, when the battle was raging between documentary as journalism and as artistic endeavour. How high-minded it all seems now that television's mainspring is the irresistibly profitable premium-rate phone call.

Just as suddenly he is in film, wooed away from Swinging London by Hollywood. Here is the succulent meat of the book, as he takes us through each of his dozen movies over almost 25 years. But this never degenerates into mere movie-set anec-dotage. Boorman is too acute and informative, too serious and funny, catching us off guard with sudden bursts of deeply affecting writing. More than once I had to stop reading for several moments after treading on one of his emotional landmines.

David Ash is a maker of award-winning television documentaries, including The Second Russian Revolution and Israel and the Arabs - The 50 Years War .