Pennie Smith's images include the defining photograph of The Clash - and, oddly, one of Aslan, writes Tony Clayton-Lea.

She doesn't use colour film. She hates using a flash. She doesn't ask the people she photographs to pose. "If I'm talking to people and, bang, a flash goes off in their faces they look shocked. Also, being front of stage taking flashes is like letting off machine-gun fire: it destroys the atmosphere."

There are only minutes until the opening of Dublin Calling, Pennie Smith's first exhibition in the Republic, and she's having none of that nonsense about being one of the best rock-music photographers of all time. "I've been discovered again, somehow," she remarks about the regard with which she's now held in the mainstream - a regard rock fans have long had. "Maybe it's the liking for guitar music over the past year or so. I also think photography has become a saleable art medium. Ultimately I'm a jobbing photographer who has carved her own niche. I've been very lucky."

Now in her 50s, Smith has been taking photographs of rock bands, singers and musicians for more than 30 years. She started working for New Musical Express in the British paper's hip, gunslinger phase, an almost mythological period when writers such as Nick Kent and Charles Shaar Murray travelled the world, interviewing The Rolling Stones, Led Zeppelin and other rock 'n' roll icons.

She's as busy as ever, with a work ethic that seems equal parts abstract and ambitious. Work she describes as swotting-up, such as an archive for her undeveloped website, remains a low priority. "I'd rather work on something interesting," says Smith, who is horrified to admit how long she has been "shooting", pointing out that the people she has been working with recently, notably The Strokes, weren't even born when she began.

Always at the back of her mind, she says, was a sense of not working for posterity, hence her bemusement at seeing her photographs in a gallery. The 40 or so images at the Helix, Dublin City University's arts centre, are a small sample of Smith's output, but they nevertheless encapsulate what she finds interesting about rock musicians: ugly or beautiful, they express a mixture of ego, otherness and commitment to style and revolt.

It doesn't matter whether she likes the musicians. What's important is empathy. "It's not like I need to be chums with them or they with me," she says. "But I have to appreciate that on the road it's their own space, and if you didn't like someone whilst travelling on a bus for a few weeks that'd be a nightmare. It's really about feeling comfortable with people. All the bands I regularly work with are people I wouldn't necessarily speak to after the job. They let me get on with the job and I let them get on with theirs.

"On the road it's the same: we read, we watch a movie and I don't get in their face until I have a camera in my hands. Usually by the second day with a band I'm invisible to them, which says very little for my charisma. After a while they seem to think that I'm not enemy aircraft - what I do is what I do."

And what Smith does is take great monochrome photographs: compositionally quirky, of the moment, visually arresting and quite likely capturing the essence of the star. She's photographed pretty much every well-known band you can think of - she shot most of NME's covers from 1972 to 1982 - and several you thought you'd forgotten, such as Mansun and, bizarrely, Aslan. She makes a veiled reference to U2, whom she once photographed. For whatever reason, the photographs "didn't work out for my benefit or perhaps theirs".

What makes her work enjoyable, she says, is the people she works with and the art of it. Ironically it isn't the music. "I'm tone deaf. It's shocking, isn't it? I get invited to all the studios and the album launches. I'm asked what I think and I haven't got a clue. I'm the kind of photographer who isn't waiting for someone to tune up their guitar.

"I can see the visual build-up of what might happen next, which has probably got nothing to do with the noise coming from the stage. Sometimes I'm asked what I thought the gig was like and I can quite genuinely say I didn't hear it.

"If you're looking through a camera you aren't aware of what's going on. You're watching and hoping that the light changes at the right point for you to snap a good one. Of course I couldn't be on the road with a band if I didn't like their music in an overall sense, at the very least, but it's more to do with the people I'm with, like any job."

Is there anyone she has photographed and hasn't liked? Debbie Harry of Blondie was having a bad hair day when Smith arrived for a photo shoot many years ago. "She just didn't want to know. I shot her and left, but that photo worked out." Politicians don't inspire her. "I found them weird to photograph. The lot that I did [for NME in the early 1980s\] were on their best posing positions. I couldn't get my teeth into them at all. It was sterile: here comes the photographer, let's just sit here and be terminally boring."

Prize-fighting photography dragged her away from rock 'n' roll for a while, but she left it behind when she realised she couldn't see as many dimensions with boxing as she could with music.

"I like the bunker mentality of a rock band on the road. I travel with my camera, not too much equipment and one bag, just doing my job. I like the kamikaze sense of whether the photos come out or not.

"As soon as photography gets into poncey studios, lighting directors and make-up artists I'm out the window. That's what I like the rock business for, because it's not quite civilised society."

Discovering that she's backing herself into a career corner through self-indulgence, she generally takes on projects and work only on her terms. "I probably get paid enough money now to be a bit snotty about who I do and don't work with," she says.

"I'd got wind of The Strokes early on and I found them so interesting. Once I saw them I knew there was no other place on the planet I'd rather be than right in their room, taking their photographs. There was an instant mutual liking.

"The Strokes excepting, I don't translate well to America. They think I'm far too grubby - I've not got the right nail varnish; I don't even clean my nails." We look at her nails and realise that, yes, the US will never take her to its heart.

She stops short, says that she's spoken far too much, that the exhibition is due to start very shortly and that she's gagging for a smoke. She returns, sated, seconds before the opening. Her timing, as usual, is perfect.

Smith chooses to disagree. "As a photographer you're hopefully there a nanosecond before the right moment. If you're there at exactly the right moment then you've missed the shot, haven't you?"

Dublin Calling, an exhibition of Pennie Smith's photography, runs at the Helix, Dublin, until November 3rd

On her picture of Paul Simonon of The Clash:

"I'm so familiar with it that I can't assess it," Pennie Smith says of her iconic image of Paul Simonon of The Clash, above, which Q magazine named the best rock 'n' roll photograph of all time. "I'm astonished that it's taken off so well. For me, taking it, it was feeling that something was about to happen. I saw Paul Simonon lift his guitar from his shoulder, wondered what he was going to do with it, knew he was coming my way and just took the shot. It wasn't a constructive photo, rather like tiger-hunting in the old days: will I get the tiger or will the tiger get me? It's only recently I've come to realise perhaps the reason it's loved so much is that it's a bloke's thing. It also works because it was so unusual for Paul to do something like that - he's so gentle, so straightforwardly ethical - Mr Cool losing his temper . . . If it had been in focus the image would have died."