'My best pictures have come when I've been the least certain and most anxious,' admits Chris Killip who, despite his angst, produced one of the most honest and assured photobooks of the late 20th century, and has been a teaching professor at Harvard University ever since.

'Here I am in a field or a deserted street and I'm scared. Where's that coming from? Do I think the ground is going to open up and swallow me? No. I'm scared because I'm getting to the point where it's no longer recognisable, and I'm pushing it.

'But when I take a picture and think to myself, "That's good", I'm cautious. Then I tend to think, "Oh, you're kidding yourself again! I bet that's somebody else's picture you've just taken". Because if you "know" it's good, how do you know it's good? Because it's familiar. You always have to go a little bit further than that. So, it's a good place to be when you're working outside your own canon or orthodoxy.'

It's a philosophy Killip might have applied to his entire 35-year career, which he himself describes as 'very odd', and which has proved anything but orthodox. Despite his status as the key forerunner to a generation of celebrated British documentary photographers that included Martin Parr, Paul Graham and Tom Wood, he never joined an agency, despite some good offers, and has only published four books, the last of which has just been released.

Professor of Visual and Environmental Studies at Harvard, he left school at 16 with no qualifications. And although he's been shown in some of the most prestigious photography venues in the world, he's happiest when he sees his images in someone else's family album. 'There have been lots of things for me that showed, well, you never know,' he laughs. 'You think all is lost, then suddenly it isn't. It seems something will never happen, then it does - but not for the reasons you think or in the way you wanted or expected. Chance plays a big role in everybody's life. But am I opinionated, stubborn, pig headed, over-obsessive? Yes, I am a bit like that. But why not? It's a sink or swim thing then.'

Decisive moments

Born and raised on the Isle of Man, Killip got into photography by accident when he came across Henri Cartier-Bresson's Rue de Mouffetard 1954 in Paris Match. Aged 16 and freshly kicked out of school, he spontaneously decided to become a photographer and got a job touting tourists on the beach - despite the fact he'd never taken a shot before. 'On the first day they gave me a Leica, and on the second day they took it off me and gave me a Kodak Redneck 2V,' he laughs.

He didn't learn much about photography but he earned enough to head for London and try his luck at assisting. He knocked on the doors of nearly 100 advertising photographers before getting his chance. Adrian Flowers took him on, he says, largely because his first assistant at the time had a soft spot for the Manx, and desite the fact he didn't really need an extra assistant. He became an important mentor, buying Killip his first camera and asking to see the photographs he shot with it (often on film pilfered from Flowers' studio). This job led to further assisting, and Killip eventually fell in with photographer and model du jour, Justin de Villeneuve and Twiggy. Shooting with them in America in 1969 Killip stumbled on his first photography exhibition, and his second career revelation.

'I visited the permanent collection at the Museum of Modern Art in New York (one of the first major institutions to properly collect and display photographs as an art form), and I thought it was so wonderful,' he recalls. 'It proved to me that photography had a value, and you could do it for its own sake. It didn't have to be advertising or fashion. I decided there and then to go home and photograph what I knew, what I cared about and what I had access to. I said to myself: "This is like a deck of cards. You can play some cards here in your favour, or give yourself a better hand just by going back to the Isle of Man".'

Home start

And so he returned home and started shooting the island's traditional agriculture and farming industries; a series of photographs that would later be published as The Isle of Man; A Book about the Manx. He started out on 35mm, but after six months showed the project to Bill Jay (then editor of Creative Review) and was advised to try switching to large format. He saw what Jay meant after just one plate, and threw away everything he'd already shot. After that the project went quite quickly, and he'd finished it by 1972. But he didn't publish it for another eight years.

'I showed it to English publishers, but at that time - and people have forgotten this - black-and-white printing had become terrible,' he says. 'It had basically been abandoned. So every time someone agreed to publish it, I said "Great, but I don't want your printers. I want someone good and the best people are Meriden Gravure in Connecticut". Then of course they'd refuse, so I'd have to pull out. It was heartbreaking, but the whole point was that the project was shot with the photographic exactness of a plate camera. Why would I use a plate camera and print it badly? It didn't make any sense. Then finally Zwemmers said they'd publish it (in conjunction with the Arts Council) just when the pound and the dollar went crazy. I ended up getting the best printing I could get just because it was cheap!'

North country

Afterwards, Killip headed back to England, shooting a commission for the Arts Council, Two Views, Two Cities, focused on Bury St Edmunds and Huddersfield. In 1975 he won the Northern Arts/Gas Fellowship in photography, which required him to shoot gas pipelines in northern England for 20 hours a month. Basing himself in Newcastle, the low cost of living meant he was able to spend his free time 'working as industriously as I could' on personal projects. What he shot over the next few years formed the basis of In Flagrante, the now widely celebrated book that cemented Killip's place in photographic history, and shadows everything he's ever done since.

Still using a 5x4, he shot hand-held, judging distances by eye and sometimes using a flash for sharpness. It was difficult to perfect, but once he'd mastered the technique he found a looser photographic style, away from the static imagery of The Isle of Man, which was so reminiscent of Paul Strand. By night he studied photobooks, comparing his images to photographers such as Walker Evans and asking himself why his shots didn't match up.

They were tough times in Tyneside, and the photographs reflect that with brutal honesty, recording the graffiti-riddled streets and their burnt out flats among the disappearing shipyards. Most of all, he focused on the people eking out a living in the midst of it all, including those who scavenged for waste sea coal washed ashore on blackened beaches - eerie scenes that make for some of the most striking

Images in the book

Killip first visited the beaches around Lynemouth in 1975 but, he says, it took him years to win the sea coalers' trust. 'I went there when I was first in Newcastle, and I couldn't believe it,' he remembers. 'It was so odd, these guys getting coal from the sea, and so visually amazing with all these horses and carts. But when I went on the beach with my camera, they just turned around and tried to run me down. I pulled off the beach and didn't go back for two years. When I did, the same thing happened. This continued until 1981, when I had a very bad afternoon and decided to go to the sea coalers' local to reason with them. They said "Listen, we get photographed by the dole. They sit in the van and they spy on us, and then when we go to get welfare they produce these photographs and we won't get any money. For us photographs are bad news, and we don't want any."

'Then, suddenly, the door burst open and this guy came in and said, "Hey, what are you doing here?" I didn't recognise him at all, but he said he knew me from a horse fair I'd been to. He asked what I was doing, and I explained that I wanted to shoot on the beach, but the guys wouldn't let me. He turned to them and said: "You lot, listen, the photographer's with me. He'll be on the beach tomorrow at eight o'clock. Any objections?" He was the local tough guy, so of course there weren't. It was amazing, so serendipitous.'

Several sea coal images made it into In Flagrante but Killip says he has about 200 more he wants to publish. He's currently working on a new book, designed along constructivist lines. 'I didn't believe photography would change the peoples' conditions, but I thought they were important and that their lives were worth recording,' he says. 'There's the written history and then there's what happened, and I always think photography is closer to the latter. I was very conscious when I was photographing that this was what was happening, and that it wasn't going to last.'

In Flagrante

By then Killip was also an active founder member of the Side Gallery in Newcastle, the photo-graphic genesis of the Amber Collective set up by a group of leftwing documentary filmmakers. In 1985 he and another member, Graham Smith, staged a joint show in London's Serpentine Gallery, Another Country. It won instant critical respect but was slated by the mainstream press, particularly in the North East. 'The Sunday papers in Newcastle said the pictures shouldn't be hung; those two should be hung instead,' laughs Killip. 'What we were presenting was a reality, but it wasn't the North East - modern, and adapted for the computer industry - they wanted to show. It would be very different now.'

He also guest-edited an edition of Creative Camera with Peter Turner around the same time, which led to an open invitation from David Godwin, the managing director of Secker & Warburg, to publish a photobook. He sat on the invitation for two years before taking it up, and when he did he gave Godwin some strict terms - he would work with the editor Mark Holborn, and Secker & Warburg would publish the book without interference. Godwin immediately agreed.

'Mark had been looking at the top end of work in America thinking about the narrative possibility of a book,' says Killip. 'He'd worked on Nan Goldin's The Ballad of Sexual Dependency, as well as Creative Camera and Aperture. I'd come down to London with a dummy that I'd been working on for three weeks, he'd find flaws, and I'd have to go outside and smoke a cigarette and kick the wall. It was tense but positive - we both wanted it to be as good as it could be.'

Touchingly, Killip is just as proud of another, more humble use of his work - his subjects' family albums. 'The greatest moments I've had in photography have been the small private pleasures of going through their photo albums and seeing my photos popping up every now and again,' he says. 'These little black-and-white photographs mixed in with their pictures, as important as their snapshots as part of their history. It's good to see that my images have another life, and it's just as important as any other life.'

Ivy league

This thinking has continued to inform his work, both as a photographer and as professor at Harvard. Killip got a call from the elite American university in 1991, around the same time Newcastle Polytechnic rejected him for a more junior role, and once he made his mind up to go - he laughs that he only went because nobody else was asking and he needed to put his son through college - he never looked back. He's now an American citizen, and he's overseen the university's photography course in characteristically anarchic style. His students are rocket fuel, the brightest in the country, he says, but he worries they can have rather limited world views. He sees it as his duty to shake them up, and has enlisted photographers such as Boris Mikhailov, David Goldblatt, Joan Fontcuberta and Nan Goldin to do just that.

'The worry for American students is their insularity,' he says. 'So it's terrifically important to bring in people from other cultures. Boris was the best. I brought him in and four weeks later the students asked me to get rid of him because he was mad. He said black was white, they said, he couldn't agree on anything. "Yes, he's very different," I said. "Get on with it." They got him in the end.'

Killip particularly admires Mikhailov's lack of respect for the photographic image - the Russian throws prints around in lectures - and says he fights hard to make his students prioritise the content of their images over so-called artful presentation. 'If they want to photograph in black-and-white, I ask them if they're 60 years old,' he says. 'If they want to photograph in film I tell them they're mad. I write terrible, terrible things about Ansel Adams, using him as an example of how moribund photography became in America with the print as a fetishised object.

'If I sent them off to a lab and made them come back with all their photographs postcard size they'd be terrified, because it looks too much like a snapshot. I have to ask them, "What's your problem with a snapshot?". They've got this false demarcation where snapshots aren't important, where in fact they could be the most important thing, because you're photographing what you're responding to. And then there's communication - people don't have many inhibitions about looking at snapshots or postcards, they enjoy them and feel they understand them. Photography is complicated and there are different contexts and way of looking at it, but I don't think that postcards are lesser forms.'

Irish colour

In fact, he says, snapshots and postcards informed many of the images in his latest book, Here Comes Everybody, just published by Thames & Hudson. Shot in Ireland over a series of summer visits from 1991 to 2005, it records annual religious pilgrimages alongside more everyday scenes, shot in the Gaelic speaking West Coast regions. Killip didn't shoot with a specific project or book in mind, he just photographed what appealed to him.

He also shot in colour for the first time, organising the book into a series of black-and-white and colour spreads, and cropping the 120 film monochrome images to match the 35mm colour. The result takes the viewer back and forth between past and present, contrasting the difficulties of the penitent's pilgrimages with sun-strewn landscapes and beaches, while evoking the easy-going accessibility of the postcard.

'I met Liam Blake and Peter Zola, the two main Irish postcard makers, when I was over there and I thought they had the ideal job,' he says. 'They don't work too hard and they know an awful lot about the land and the landscape. I had this fantasy that I would be an Irish postcard photographer.'

Killip started shooting colour in 1997, inspired by Goldin and her seminars at Harvard. She asked all her class to buy a Yashica T4, an inexpensive colour film camera, and Killip decided give it a whirl too, 'photographing in colour without making a big deal of it'. He liked it enough to take it to Ireland, but when fellow photographer Tom Wood laughingly asked him when he was going to get a real point-and-shoot, realised it was time to get a Leica.

But what really got him into colour photography was digital post-production, and the realisation he could tone down the vivid film colours. 'Kodak and Fujifilm want peoples' skin to be warm, the grass to be bright and the sky to be blue, but for me it was just too glossy,' he says. 'It made Ireland look like the south of France.'

Digital future

In fact, Killip is quite a digital aficionado. Although he printed his own images for years he says the idea that you need to have printed to photograph is 'nonsense', and even questions whether photobooks will stay the course. Anarchic and provocative to the last, Killip is a true original and a genuine free thinker.

'I'll get all my students to publish Blurb photobooks - it's a brilliant way to get them to think about text and narrative,' he says. 'But I don't necessarily think that photobooks are going to last or be as important in the future as they are now. There are going to be other things. You see how websites are changing. Some of my students are working as news photographers now; they're all carrying video cameras. The still image isn't enough any more, there are voice-overs and recordings. Photography is now part of the media world.'

In print

Here Comes Everybody by Chris Killip is published by Thames & Hudson (ISBN ISBN 978-0500543658), priced £30.

Errata Editions recently published a 'book on a book' version of Chris Killip's In Flagrante, presenting the covers, spreads and essays originally published plus a new essay by Gerry Badger (ISBN 978-1-935004-06-0), priced $40. Visit errataeditions.com