Barbara Hershey: My brilliant career

She's seduced Jesus for Martin Scorsese and been pushed to the limit by Jane Campion ? Barbara Hershey is an actress who won't play it safe. She tells Fiona Morrow what drives her

Barbara Hershey is a good deal smaller than I had imagined. Not just slender – which movie-actress isn't these days? – but petite with it. It surprises me because Hershey feels big on screen: she can project strength, vulnerability and passion equally forcefully, but in the subtlest of ways. It's what, I suppose, is meant by screen presence. In her simple black trouser suit, her brown hair straightened and falling just below her shoulders, there's something almost childlike about her.

And, talking to her, she feels younger, too; she has a youthful spirit. Maybe it's left-over from her hippie phase (when she changed her name to Barbara Seagull), or perhaps it's what drew her to the counterculture in the first place. Whatever, Hershey's evident intelligence and thoughtfulness is balanced with an instantly engaging optimism and humour.

She began working seriously as an actress in 1966, aged 18 – and she's hardly stopped for breath since. She has appeared in 56 films, not all of them easily remembered, and a few best forgotten. But that, Hershey acknowledges with a smile, is inevitable if you like to work. And anyway, there's the clutch of great performances in great movies: The Right Stuff, The Stunt Man, Hannah and Her Sisters, The Last Temptation of Christ, Tin Men, A Portrait of a Lady... Two or three of those alone would do most people proud.

Her latest, Lantana, ranks among the better films. Directed by Ray Lawrence, it stars Anthony LaPaglia as a middle-aged cop whose work has numbed him to life. Hershey is Valerie, a psychiatrist whose 12-year-old daughter was murdered; all her attempts to cope distance her further from her husband John (Geoffrey Rush). But this isn't a film that can be summed up by its plot: it's a beautifully judged ensemble piece and an intelligent, compassionate and, at times, disconcertingly honest study of human behaviour.

As Valerie, Hershey is a walking tragedy, deeply pained, losing her grip on reality, over-sensitised to every nuance of human interaction. It's a terrible state for her to suffer, both as psychiatrist (she's unable to retain her objectivity) and individual (her patient's problems become enmeshed with, and deepen, her own).

"I was very touched by her plight," Hershey comments. "Any mother – but probably anyone – can imagine that to lose a child is the worst thing that can happen to you. But to lose one so brutally – what could possibly be worse?" Shooting on Lantana had already begun by the time Hershey was signed up. The Australian production had looked for a Valeria at home first, before venturing abroad. "I often come to projects late," she laughs. "I've started to call myself the '11th-hour woman'."

I ask her if turning up to a set that's already underway was daunting, and her response is quick: "No – well, it's the right kind of daunting. What's difficult is when you're trying to make something out of a script that isn't very good. But when you're confronted by a great piece of material – which I think this is – what's daunting is, 'Can I come through? Will I come through?'."

She drops her voice slightly to add: "When it's a beautiful piece of material, you just want to honour it." Lantana, she says, was that rare thing – something she hadn't seen before: "At first I thought it was a thriller, and then I realised it was a kind of mystery, but of human relationships. I thought it was funny and frightening and I was blown away by the fact that the climax is not full of explosions, but really gentle, chilling revelations."

Hershey speaks softly, her voice containing just enough low notes to give it an enviable breathy timbre. When she talks of explosions and revelations, there is a tiny tremor added, imbuing her statements with a sense of drama. The structure of Lantana meant that she only worked with a few of the other actors, principally Geoffrey Rush: "It was a pleasure acting with him," she proffers sincerely. "Those eyes – that jail he's in – John's so tortured and angry, so closed down. And I just thought it was an incredible, restrained performance."

"Sometimes when you're doing an intimate scene and you look into the other actor's eyes, all you see is a little bit of panic or something," she continues, pulling a comedy grimace. "But whenever I looked into Geoffrey's eyes, he was so completely present – it was just incredible."

She also had a good relationship with the director: "He shot the film without lights," she explains, pulling gently at her hair. "Which is why we look the way we do." The latter is said with a laugh but, one senses Hershey didn't relish being so exposed. Nevertheless, she says she admires the film's gritty look and has nothing but praise for Lawrence: "I like an affirmative atmosphere and I love it when the director and I work well together – then you're not alone. The director is objective and I can be subjective – which is how I like to act. When it works it's heaven on earth to me."

It may sound like hyperbole, but that's not something Hershey appears prone to. Acting clearly means that much to her: "I love it. It's the one thing that has seen me through the roller-coaster of this business. It's the one thing that is constant and the one thing that will never leave me."

I mention that I'd read that on Portrait of a Lady Jane Campion had pushed her almost to collapse and, unexpectedly, Hershey bristles: "Don't believe what you read, people do sensationalise," she says with a frown before asking me to expand.

"That's true," she finally concedes, when I read her the quote. "And she is a very challenging director, but I don't mind that. I also want to see how far I can go. Sometimes it's just delicious, acting," she continues unprompted. "It's such a great experience when you plug into some real place and it's happening to you. It is a kind of ecstasy.

"But I've also had directors be too easily pleased and part of you thinks, 'Could we have tried harder?' You don't feel that with Jane – with Jane you know that you went there. That you went everywhere."

One of the things Hershey is famous for is, on the set of Boxcar Bertha in 1972, handing a young Martin Scorsese Kazantzakis's novel,The Last Temptation Of Christ, and eventually starring in Scorsese's film version in 1988. As we're winding up, I ask Hershey if she's handed out any other novels since, and she lets out a gleeful whoop of laughter: "No, and I should," she says, "But who on earth would I give them to?"

The making of that film, was the experience to top them all: "That was way beyond a film for me and, I think for Marty too," she recalls, taking a moment to relive the memory. "If I could play one role forever with one director, that would be it," she smiles. "I've had some really wonderful roles, but to play Mary Magdalene with Martin Scorsese directing you, that's not bad. Not bad at all."

'Lantana' opens on 16 August