Critics and audiences have felt that way too about her recent work. In 1990 An Angel at My Table, a three-hour adaptation of NewZealand novelist Janet Frame's autobiography starring Kerry Fox, became an international hit. The Piano looks set to eclipse that, having won the Palme d'Or at Cannes and with it the sexist accolade, 'the greatest film made by a woman'.
'I've probably terrorised you,' Campion says, seeing me across a London hotel lobby. Harvey Keitel feared 'being struck by a thunderbolt' from his goddess. My fear - yelled in body language across the plush foyer - is of a more mundane scrape. Someone from the Campion camp has told me that an article I wrote on Keitel's co-star, Holly Hunter, intended as appreciative, was taken by the director as sarcastic.
With her warm, open manner and the look of a Pre-Raphaelite recently out of art school, Campion turns out an unlikely terrorist. The Hunter issue is soon smoothed over. Campion tells me: 'I don't intend to intimidate you into . . . (a burst of the laughter that will punctuate the interview) . . . into anything.' In that remark, you can detect something of her distinction as a director: her feel for the subtleties and strategies of relationships. She shows a quick, intuitive understanding of the way people's minds work - which must be a joy for actors - and a clear, humorous way of conveying it. Her elegant, flowing sentences end with an upward lilt, offering their points for your approval.
If communication is her gift, it's also her subject. Campion's films throng with characters struggling to be heard in the world: the little girl in the early, half-hour A Girl's Own Story (1984), acting as interpreter for her non-speaking parents; warring families in the award-winning short, Peel, a seven-minute row between three redheads over a piece of orange dropped from a car, and in Sweetie (1989), in which the loopy heroine tries to assert herself as an artist through a trick with a chair, while her sister wonders why she's in a 'no-sex stage' with her boyfriend; and, most movingly, in An Angel at My Table, Janet Frame finding on paper a voice which chronic shyness mutes in person.
And on to The Piano, whose non-speaking heroine Ada, shipped from Scotland to New Zealand and an arranged marriage, expresses herself through her small daughter and her piano. This is from choice rather than handicap, Campion suggests: 'She is sympathetically out of step with the rest of the world: too extreme, too purist, too wild - particularly in Victorian times - to be understood. She has too high motives, and the world will always disappoint her. The piano enables her to have a voice, becoming almost indistinguishable from herself. Their fates are linked. And because she doesn't speak, her intimacy with people becomes more instinctive and physical. Which takes us into the area that the film is exploring about eroticism and fetishism.'
Passion and the perverse run through Campion's films. In The Piano they meet head on, and melt into one another. Harvey Keitel, as Baines, a Scots settler, falls for Ada, buys the piano, and barters it, key by key, for sexual favours. What starts out close to exploitation turns into tenderness. 'He never forces her to do anything,' Campion says. 'He may start by pushing her, but he finds it important for her to come to him willingly. He wants to be loved: which is what separates him from a psychopath, who wouldn't believe that anybody could love him.'
Nobody has a closer grasp of the nuances of her films than Campion herself. She can sound more like a critic than a director, and she seems to understand her characters as if she had known them for years (in the case of The Piano's, she has, having conceived the idea just after leaving film school). But she is not doctrinaire about her work, believing The Piano resists fixed interpretation as a sexual or colonial allegory. 'It feels rich in possible metaphorical meanings, but it seems to elude any one: it's more akin to fairytale, the archetypal.' All her work has this elusive quality, its themes consistent, its tone shifting. As a director, she is lyrical and ironic, old-fashioned and modern, feminist and universal, a novice and, already, a master.
SHE WAS born in Waikanae, New Zealand, in 1954, into a theatrical family: her parents trained at the Old Vic in London, before starting New Zealand's first official touring company - a roaring financial failure. The family's ancestry is uncertain. When I ask Campion if she is related to the English Catholic martyr, Edmund Campion, she says: 'He was my great, great, great . . .' before dissolving into laughter. 'He probably was, but I don't know what my ancestral roots are. Like many colonials, I have a strange sense that my history began when my ancestors arrived. You feel cut off from European history, which seems insubstantial beside the culture of the Maoris, whose ancestry goes back so far and is so important to them.'
New Zealand, Edenic but menacing, plays a large part in The Piano, rather as it did in Alison Maclean's Crush earlier this year: the wildness and sensuality of the love story are reflected in the lush green of the jungle-like bush and the tempestuous climate. Campion is surprised that her small, far-flung country should arouse such interest and is pleased to have shared its exoticism, but doubts she'll film there again. She is now settled in Sydney and married to an Australian, the TV director Colin Englert. She describes herself as an Australasian film-maker, and feels little of the sense of being dominated by the brash, big brother that goads many of her compatriots.
Her sister Anna is also a film-maker. Their childhood, 'a fairly happy time' of putting on plays and shows, has echoes of the Bronte sisters - an influence on Jane's imagination and the romantic world of The Piano - writing for each other in the parsonage at Haworth. 'I grew up having a very long-running, serialised imaginative world. Every day after school we'd go back into a favourite game or drama, and pick up the next episode, fully costumed. So when I discovered film-making it was like going back into my childhood world, which had felt very free and sustaining. When I enjoy filming now, it's the same feeling of play-acting, making up very expensive fantasies.'
Her teenage years were more troubled - 'I was particularly disgusting and rebellious' - and may be reflected in A Girl's Own Story, which she wrote as well as directed. It captures the rite of passage in all its agonising, out-of-control complication. Encroaching sexuality is seen as something at first strange and funny - girls practising kissing with masks of favourite Beatles on their faces - and later dangerous. A game between a brother and sister leads to the girl getting pregnant and being sent to a nunnery. The brother visits, awkwardly refusing to kiss, and the two comment on the baby's tiny feet. They are parents but still children. The film closes with an ice-skater in white twisting on her blades superimposed over a girl's listless face and underneath a song with lyrics by Campion: 'Fear the cold. Fear the cold is here to stay. Want to get away.'
She got away to Australia, readinganthropology at Melbourne University. Then, after spells in Italy and England, she studied art in Sydney and made Tissues, a short weepie about a father arrested for child molestation, which had a tissue in every scene. She went on to the Australian Film and Television School (she is a good advertisement for perpetual studentship). There she made A Girl's Own Story, and met Gerard Lee, whose delicate irony was to contribute to the writing of both Sweetie and Passionless Moments (1984). The 12-minute Passionless Moments opened on the whale-like belly of a man practising yoga and making out the words on a painting - 'Sex is a Wonderful and Natural Thing' - and offered up snatches of quirkiness such as a girl in a snorkel and goggles fitting Monopoly notes on a Scotties box, and a boy imagining his bag of beans is detonated to explode in 30 seconds. It established Campion's genius for the bizarre and the fleeting.
She proved too offbeat for her tutors at film school, who didn't rate her and discouraged her from completing Peel - a blessing, since they left her alone. She didn't see how she could pursue her own vision, until her short films were rapturously received at Cannes in 1986, Peel winning the Palme d'Or for Best Short. Watching audiences at Cannes and other festivals made her aware that there was an interest in her kind of work: 'It gave me the confidence to want to give them more and to experiment with my own style.'
IF STYLE is the woman, she is protean. Some directors have a fixed cinematic personality; Campion compares herself to an actor, matching her manner to the needs of the film. If one thing unites the look of her films, it's her iconoclastic eye. It's most noticeable in Sweetie, where everything is viewed from an unexpected angle. Campion films an abortive love scene from behind a wall, so that the lovers are half-obscured, only their legs visible, awkwardly apart. Elsewhere the camera peers down or squints up: the earth seems shorn from its moorings. Shot in bold primary colours, the film is both saturated and minimalist.
You can see an affinity with Janet Frame, whose novels, though grounded in realism, explore the relation of language to the world, sceptical of conventional reality. Campion does the same with her camera. 'I distrust the idea that there's a set way everything is seen. Things occur to you differently from where you happen to be looking. The old-fashioned wide-shot, over-the-shoulder shot, close-up - it's not possible to make films like mine in that style. It's too lazy for most audiences now.'
Sweetie's strangeness offended some of its first audience at Cannes in 1989, drawing boos as well as cheers. It was not what was expected of Australian cinema - and that was part of the point. By the late Eighties the new wave of Australian film-making had settled into stagnancy: directors Campion admired, like Bruce Beresford, George Miller and Peter Weir, had left for Hollywood. 'We all felt like saying that there are other things in Australia than the cliched images people were emphasising. Most of Australia, for instance, lives in cities, the same sort of urban situation as people all over the world. It was as if the Australia we knew was a saleable lie.'
Part of that lie was a macho, Antipodean swagger. Australian cinema was impersonal, old-fashioned and male. It's still dominated by men, but women, such as Campion, her film-school contemporary Jocelyn Moorhouse, and an early heroine, Gillian Armstrong, have made more inroads than elsewhere - especially America and Britain, where Campion describes it as 'unfathomable' that there are so few women directing. She attributes much of Australia's relative enlightenment to the feminist lobby, which badgered the government agencies that ran the film industry in the Seventies and early Eighties, to the point where they were terrified of not supporting women.' Women operate very well where there are rules, getting what they can out of them, but not where it's an old-boy network, more to do with male bonding, drinking, and deals.'
She wrote the treatment of The Piano soon after leaving film school, as an attempt at something that no one else was doing. As a woman, she felt she'd have a different perspective on a story of love and sex. She had wanted to start a company that made soft erotic films for women - 'I always had lowly ambitions, you see.' When she finally made The Piano, she aimed to make it a 'feminine epic'. She does this through quirky touches and 'a delight in the charm of things'. Scouting locations, she spotted a group of hills like little waves - 'I thought that's really me: I just love that.' So she had the child running over them at the climax of the film, a tiny silhouette on the undulating landscape (too tiny, it turned out: they had to use a 6 ft girl).
That enthusiasm for the hills is very Campion: she comes across as, in the best sense, an amateur, her profession springing out of her passion, her collaborators becoming close friends. In the credits for The Piano she thanks not only the actors in the film, but those who auditioned and those who were cut. It's hard to imagine Coppola or Tarantino doing that: or either of them practising with their other half, as Campion did before facing her Hollywood stars, 'talking to people in an unbossy way, in order to gain their co-operation and the best of their ideas'.
Humility is at the heart of Janet Frame's appeal in An Angel at My Table. Campion describes her as 'an unremarkable heroine who allowed people to experience their own vulnerability'. In the last part of the trilogy, in which Janet, having been released from her false diagnosis as a schizophrenic, travels Europe, there is a scene in France, where she comes across a young man she has met before. He is drinking with friends, and gives her the cold shoulder, letting her shamble shyly away. 'It's remarkable,' mocks one of the group. 'I didn't think there were people like that. She's really, really nervous.' But, of course, Janet's gaucherie is much closer to most of us than the beautiful self-assurance of conventional movie characters.
An Angel At My Table was made as a three-part television series. Campion was initially reluctant to let it be released theatrically. When she relented it won several prizes at the 1990 Venice Film Festival, and was a hit world-wide, with the exception of Germany. Campion's wonderful eye seemed embedded in Janet's anxious, artistic mind. The opening was a Joycean essay on childhood and memory, rich in boldly colourful images, and with a growing sense of sexuality and the power of words. Like much of Campion's work, the film pushes at the thin partition between madness and creativity.
Angel was also that rare thing, a successful literary adaptation. Laura Jones's screenplay used quotation sparingly but tellingly, such as at the moment when Janet undergoes electric shock treatment and we hear her describe it as 'like the fear of execution'. And Jones's and Campion's passion for the books was plain. Campion curbed her wilder flights of style to Janet's vision, while showing a deft feel for period, particularly the bohemian Fifties literary world in which Janet spends some of her happiest times, with its young men in tweed jackets spouting Yeats and bespectacled, polo-necked American academics.
It was a literary triumph for an uncommonly literary director, who these days finds less nurture in films than in novels - 'story-type . . . Donna Tartt's Secret History over more explorative, modernistic work'. The Piano feels steeped in literary tradition, entirely original but rich in reverberations. It's Wuthering Heights, a romance of the soul, with the wild New Zealand beaches and bush standing in for the stark moors. It's Emily Dickinson: both the woman, reclusive like Ada, and the work, with its wavering between ecstasy and terror, eroticism and renunciation. It's Graham Greene's The Basement Room (filmed by Carol Reed as The Fallen Idol), in which, as here, a child is witness to an adulterous affair involving a man named Baines. You can go on: there's carnal bargaining, as in The Merchant of Venice; there's social comedy, from a pair of prim maiden aunts, as in Jane Austen.
But Jane is less aJaneite than a Jamesian. Nobody is better at turning the screw on childhood innocence than Campion: what the little girl knows in The Piano is akin to What Maisie Knew. Campion has James's unease, his understanding of the colonial relationship and gift for strong, complex characters, especially women. Her next film will be James's The Portrait of a Lady. She has thrown herself into the preparations after the heartbreak of the death of her first child, a son, who was born in the summer but lived only 12 days.
She has cast the talented but underused Australian actress Nicole Kidman as the book's heroine, Isabel Archer. Planning for the film is afoot: a visit to James's house at Rye the day before our interview; a look at portraits in the Uffizi, before it was bombed. Campion unravels for me a few layers of James's famously ambivalent conclusion, about whose meaning she is in constant discussion with Laura Jones, who will again adapt.
Isabel Archer, beautiful and poised, tumbling into the wrong suitor's arms, is a change from Campion's other heroines, who have been troubled, ordinary women. Campion has said that in her youth she felt a closeness to Archer, a sense of having great potential without knowing how to tap it. Now, aware of the quality of her work without claiming the 'intellect or genius you expect of film-makers - though we're all rather less innocent about that now]', she's both forthright and self-effacing, Isabel Archer and Janet Frame. She once said that growing up she had merely hoped to be a consort to a talented man. I reminded her of the remark, expecting rueful recognition of a lost, tentative self. 'I think mainly I still am a consort to some very interesting people,' she replied. 'It's just that they're characters in films.'
'The Piano' (15) opens on 29 Oct at the Lumiere (071-836 0691), Plaza (071-497 9999), Warner West End (071-437 4343), MGM Tottenham Court Road (071-636 6148) and Screen on the Hill (071-435 3366). It goes on general release the same day.