big shot

He says he is a prude, but Nick Knight has been photographing a lot of nudes recently. He shot the model Sophie Dahl for i-D magazine in all her curvaceous glory - except that her curves were not glorious enough. When she arrived at the studio, Ms Dahl had been on a diet. "I curved her up on the Paint Box and made her tummy bigger, her breasts bigger, her bottom bigger," he says. That's why the images in i-D's New Beauty issue in March looked a little unreal, as though this was a body that had been gently eased from a jelly mould. Not only does the camera lie, but the computer paint box can triple your cup size with one single swoop of the mouse. As Knight admits, photography is not a good medium to record reality: "If you want reality, look out of the window."

Fashion photographers traditionally spend hours in the darkroom - re- touching, streamlining, shaving off a slight hip bulge here, a dimple in the bum there. Nick Knight, however, has perfected the art of enhancement. He also has the great gift of anticipating trends. The shoot with Dahl made her an instant celebrity. Then he was credited with another fashion coup.

Readers of Vogue, usually dedicated at this time of year to skinny girls on tropical beaches wearing nothing but a few straps of elastic, were treated to the sight of a creamy-white, size-l6 girl photographed in the same few straps by Knight. These images were not enhanced. Sara Morrison, the Liverpool textiles student, appears as she is, with Knight's camera lingering lovingly on the swell of the calf, the crease at the back of the knee, the plumpness of the hand. These are not pictures documenting cellulite, bulging ankles or stretch marks; they are about Botticelli curves, a glowing roundness.

Sara Morrison is about as representative of the common woman's shape as Kate Moss or Jodie Kidd, which is why it took Knight and his assistant, Travis, several newspaper ads and two years to find her. Before the Vogue shoot, publication of which was held up after the Omega watch anorexia scandal ("a lot of hot air," scoffs Knight) for fear that they would be accused of sensation-seeking, Knight tried Sara out for the cover of Suede's "Saturday Night" single.

"I wanted to show a different image of woman," says Knight, whose own lanky body is clad when I meet him in navy pinstripe trousers and waistcoat. "My wife, Charlotte, is Sara's shape. You fall in love with someone because of the person within, not because of their shape. It isn't about perfection. I felt like I was doing something that needed doing. If those pictures can make people feel happy with the way they are, then that's great."

Knight was inspired to this by Tamara Lempicka's paintings of typically big, powerful women. "I thought the pictures with Sara worked. They didn't make her look freakish. I hope they made her look powerful and intelligent. This is an image of woman that isn't current right now. I told Travis I wanted a woman who is curvy in a healthy way. I didn't want her to look like she'd eaten too much and gravity had taken its toll. I wanted her to look healthy."

As a result, the voluptuous look is suddenly all the rage. Young photographers who once liked their models pin-thin are talking about this "great idea" they have had of finding a model with curves and flesh. The fat girl has become the latest fad. Morrison has signed up with outsize model agency, Excel, which has been inundated with bookings for chat shows and catwalks, not to mention the advertising campaign for Dawn French's clothing label, French & Teague. But, as Knight points out, it is only the beginning of something, a new role-model to sit at the opposite end of the spectrum to Jodie Kidd, with all that space in-between to fill.

Nick Knight has a knack of setting agendas. He has helped shape the face of fashion in Nineties' magazines and advertising (he is responsible for this year's Volvo's ad campaign). Many of the most influential fashion photographers of this decade have come from his stable of assistants - including Corinne Day, Sean Ellis, who has just begun a contract with American Vogue, and Craig McDean. Breaking taboos is not something Knight consciously does, nor, indeed, is it something he does that often. "I don't look for taboos to break," he says, "but it's not very hard to find them, either." He is a man spurred on by "the thousand shades of grey that make life interesting".

His house in Richmond, Surrey, where he was born 38 years ago, is somehow typical of him. The street where he lives with his wife, two children and another on the way is archetypal Thirties suburbia. Pull up outside, however, and through the trees and rose bushes you glimpse a solid grey cube of concrete and glass, more nuclear bunker than the Good Life. The kids next door are kicking a ball around their driveway. They look at me suspiciously as I ring the doorbell. Inside, there is space and light. Lots of it. But this is not a sterile interior from some glossy magazine. There is a wall of his daughters' brightly coloured crayon drawings, and a mess of toys tucked down the side of the sofa.

"It's a modern house," he acknowledges. It was built in 1990 by the architect David Chipperfield. "It doesn't fit in. I don't adhere to the idea that things should fit in. In this country, there is a love of the past and a fear of the future. I don't understand this idea that everyone should fit in." Not all his neighbours have liked him knocking down the original mock Tudor. The Knights have now bought the house next door and are planning another, adjoining Chipperfield cube.

As a young student in 1979, Knight had a book of his black-and-white pictures of skinheads published. Many of the images suggested an undertow of violence, a theme that he has been exploring again for a 30-page issue of Big magazine devoted to his work. The theme of aggression is expressed by a series of abstract explosions of red gloss paint and glass, and the magazine will carry a warning on the cover. "The images are very violent," he agrees. "I wanted to explore violence in its most basic energy."

Knight has been exploring explosions since he photographed Alexander McQueen's head, apparently being ripped apart, for the Florence Biennale last year. The idea came from the film Scanners. Knight and McQueen have been collaborating ever since. They produced the image on the invite for McQueen's last show, and they are working on Bjork's latest album cover. McQueen also art-directed the Sophie Dahl magazine story, which was originally for the Biennale. "The idea was to manipulate the body and make it more sensuous than it actually is," he says.

When he left college in 1982, Knight worked for the music press and took portraits of nightlife at clubs like Taboo for i-D. His work has always had a strong point of view, and eventually he landed campaigns for Yohji Yamamoto, Martine Sitbon, Jil Sander and Levi's, and a contract with American Vogue. He has just shot with John Galliano for next autumn's Dior campaign.

Lucinda Chambers, British Vogue's fashion director, believes that "he sees a poetry in pictures - it's not just about making it modern. He really ignores fashion. I don't think it particularly interests Nick whether shoulder pads are in or out. He makes sure he works with people who really do know about fashion, but he himself is quite removed."

Chambers singles out his pictures for Vogue in November 1993 with Linda Evangelista, using ring flash. They heralded a glamour missing in fashion during the Deconstructivist, grungy late Eighties and early Nineties. "They changed fashion," she declares. According to Knight, they also shifted a hell of a lot of cosmetics from the department stores: suddenly, painted faces were back in fashion.

He has to feel passionately about a client, he says: "If I work for a magazine, I want the sales figures to go up... If sales plummet, it's difficult to justify what I'm doing." Similarly, he wants his fashion pictures, be they editorial or advertising, to sell clothes. "I am aware, increasingly, that there's an audience out there. I wouldn't ever want to be seen as irresponsible." He doesn't compromises his images to fit an audience, but he considers them at least.

After the Levi's Original Red Tab campaign in August l996, he helped the jeans company reclaim its cowboy heritage with his portraits of octogenarian ranchers from Colorado. To find the right people for the campaign, Knight sent Travis out to the States for two months. "I was shocked when the ads came out at the criticism of Josephine, the white-haired kick boxer. They said how horrible it was to show a woman of her age in a sexual light. What age are we supposed to stop being sexual? She was a strong woman. But people want to see their own lives. It's safe that way." The images themselves were essential Nick Knight - provocative, technically brilliant, and a step outside of anything else going on in fashion or photography at the time.

In every conversation, his associates talk of his desire for control - hence his use of computers to manipulate the shot in post-production; indeed, he compares in importance the development of the computer Paint Box to the invention of the wide-angle lens. He works in a very static way, with a huge plate camera that he describes as a "washing machine on legs". He painstakingly builds the image rather than snapping a moment. "It's all about intuition," he says, "about perception. Your mind needs to be finely tuned on the day of a shoot." The whole "heroin chic" debate passes him by. "When I'm doing pictures, I don't drink for days before - not even coffee."

But he frankly admits that taking pictures scares him. He even says he hates cameras. "It's like doing a performance to order. You might as well stand there naked. You have a whole team working with you, but in the end it's down to you." And there is the insecurity of it: the wind can change and you might be dropped overnight.

His suspicion of the fickle power of photography extends to photographers. He admires Cecil Beaton, Irving Penn or Guy Bourdin. "They were lyricists," he says. Who would he let take his own picture? Corinne Day or Craig McDean, perhaps. "But it would be like a knife going in"

Nick Knight is a contributor to Little Boxes, an exhibition at the Photofusion Gallery, 17a Electric Lane, London SW9 , from next Wednesday

Knight moves (above from left): Taken from his book Skinhead, published in 1982, which first brought him to public attention. `Taking pictures in this environment is so easy. The problem is persuading myself to go there and then trying to understand why I went'; Alexander McQueen Exploding Head , 1996. `I was happy that at first glance it looks like Lee's wearing some magnificent Philip Treacy hat; his graphic invitation to McQueen's show in London's Borough Market this February