ARTS / With one eye on stardom: Show People: 40. Juliette Binoche

THERE used to be an air of sweet innocence about Juliette Binoche. When she appeared in Leos Carax's The Night is Young (1986) she was a sleep-walking waif, afraid of open spaces. She had attached herself to Michel Piccoli, an ageing hood, because he could afford her protection from the outside world; and she did not so much resist the love of the young safe-cracker, Denis Lavant, as sidestep it with a tremulous innocence.

In their long, night-time heart-to- hearts, Carax dwells upon her lovely face well past the point at which the viewer's wonder gives way to embarrassment. There are times when she hardly knows where to look for shame, and her eyes become misted. Her acting here had an openness which owed more to life than performance, and brought to mind Godard's use of his wife, Anna Karina, staring her down with the camera until discomfort became an emotional truth.

Binoche had made seven French movies before that, but it was Philip Kaufman's film of Milan Kundera's The Unbearable Lightness of Being (1988) that presented her to a larger world. Everyone remembers the lady in the bowler hat. But it was Binoche who represented the awakening of political and emotional maturity of the Czech middle classes in that film. She was the frumpy little barmaid who conceives a passion for Daniel Day- Lewis, a womanising brain surgeon.

He is examining her for a cold, and when he asks her to open wide, she fastens her gaping mouth on to his and jumps him with all the awkward fervour of a convent girl finally letting loose. She is happy with the existence of his bowler- hatted mistress, with whom she shares a talent for photography, but the naked photo session that gets going between them is the sexier for Binoche's reticence.

Now all of that is about to change. No more Miss Nice Girl. In Leos Carax's latest film, Les Amants du Pont-Neuf, she is seen dashing along a shore line, towing Denis Lavant through the surf by a sensitive organ. And it isn't his nose. It is a moment of great Dionysiac release after the general squalor of their lives back in Paris. One just hopes for his sake it didn't need 25 takes.

They are a pair of down and outs who doss down on the Pont-Neuf each night. She, a middle-class painter, is already blind in one eye, with the other eye fading fast. The determination with which she keeps on painting shows us a new, tough side to Binoche.

The production notoriously ran into money problems. They had acquired permission to close the Pont-Neuf for August, when Paris is traditionally empty. But Lavant injured his wrist, and the delay meant that the bridge had to be recreated near Montpellier. Then a second lot of producers stepped in. 'It was very painful to have to keep stopping. It almost felt like three different films,' Binoche says. 'It just wasn't fair. But when you believe in something in your heart, you know you will finish it.' Fighting talk from this gauche girl who has a habit of blowing her fringe off her forehead when she thinks you aren't looking.

All of Carax's films alternate between good scenes of bravura action or strong emotion and stretches of appalling pretension which tire your patience. But there is one scene in the film which everyone will remember long after the embarrassments are forgotten. It is Bastille Day, when the French go mad with fireworks. Lavant steals a motor boat and tows Binoche down the Seine on waterskis, with the fireworks dancing on the water beside her. It is a breathtaking jeu d'esprit, not least because instead of mocking something up in the studio, he filmed it in situ, in one take, without a stuntwoman. A lot could have gone wrong, and all of it dangerous. 'I learnt to waterski especially in Florida. But that was nice and warm,' Binoche says. 'This time it was November and seven degrees below zero. The Seine was too narrow for any slaloming, so I was right in the boat's wash. And wearing the eye-patch, it was very hard to keep your balance.'

She was born in 1964 to a father who is a theatre director and sculptor, and a mother who was an actress. When they divorced she was sent to boarding schools around France, which taught her independence and the proper realisation that Paris is not the centre of the world. She first aspired to being a painter, preferring the privacy of that art to the public display of acting. The movies may have claimed her, but she keeps up the painting; she did the movie's attractive poster with brush and chinese ink.

She is speaking the kind of perfect English which only foreigners seem to achieve these days. She can even manage the dental 'th' which usually defeats ze French. This is just as well, because she has recently completed Wuthering Heights, playing Cathy opposite Ralph Fiennes's Heathcliff. She is also in Louis Malle's forthcoming Damage, taken from Josephine Hart's novel about a politician (Jeremy Irons) who conceives an obsessive passion for his son's girlfriend.

However these turn out, I will always treasure her for that vision of a spirited girl, roaring down the Seine through gaudy cataracts of fire.

'Les Amants du Pont-Neuf' (18) opens at the Lumiere (071-836 0691) on 11 Sept.