When I ask Mary McCartney to describe her mother's photographic style, she thinks for a long moment and says: 'She approached photography the way she approached everything else - with quiet confidence.'
You can see that in the photographs spread out before us on the table of the west London members' club where McCartney has met me to talk about a forthcoming exhibition of her mother's work. The show, which opens at the James Hyman Gallery on 25 April, is the first major retrospective of Linda McCartney's photography, and has been timed to coincide with the 10th anniversary of her death from breast cancer. The photographs have been selected by Paul and Mary McCartney, with input from Hyman, from 4,000-odd contact sheets.
'It's an incredible archive,' says Mary, herself a respected fashion and portrait photographer. 'Mum never stopped taking photographs, though it may have seemed that way to the public. It's about 30 years' worth of work. The only gap is around the time when Stella and I were born when, as she said, she was up to her neck in nappies. Otherwise she always seemed to have a camera in her hand.'
To many people Linda McCartney was known, first and foremost, as the wife of a Beatle, and then as a vegetarian-cum-animal rights campaigner. Yet it is her career as a photographer, which waned as she embraced motherhood, music and activism, that is her lasting legacy.
'She was an instinctive photographer and always unobtrusive,' continues Mary. 'She wasn't that interested in straight portraiture or art photography - the images she caught were nearly always intimate, relaxed and oddly revealing.'
You can see that intimacy in her shot of John Lennon and Paul McCartney working on lyrics in the corner of a recording studio. Both are immersed in the task, but obviously having a good time. McCartney, his biro poised over a sheet of paper, may just have amended the lyrics. Lennon obviously approves. They seem almost conspiratorial and to have the intimacy of a long-term couple. Which, in a way, they were.
With the Beatles, Linda's access was assured. Before she met Paul, though, she had worked with many of the icons of the Sixties pop scene, including Jimi Hendrix, whom she famously captured mid-yawn. He didn't seem to mind.
'It was a different time,' says Mary, 'before PRs and image makers took over. Back then, she told me, the manager would often be a friend of the band. If you were cool and they liked you, you could simply hang out.'
Mary's younger sister Stella, now a celebrated fashion designer, is in one of the most intriguing family snapshots. It was taken at Paul McCartney's cottage in Scotland, near the Mull of Kintyre, which he famously hymned on one of Wings's more mawkish songs. Paul balances on a fence in dressing gown and slippers. He is watching with some concern his young son James, who has just leapt off the bonnet of the family Land Rover. Immune to the drama, Stella is kneeling on the grass in the foreground, immersed in some private reverie.
'That's Poppy, our family dog,' says Mary, pointing at a pooch in the background. There is also a sack of logs, or maybe potatoes, in the foreground near Stella. It is a detailed photograph but intricately composed: the dark, looming cottage on the right of the image, the fence that arcs away to the horizon, the tall figure of Paul echoed by what appears to be a ring of standing stones in the background on the left.
It is also a perfectly rendered moment, a deceptively casual portrait of a family caught up in one of the small dramas of the everyday. The image is given added resonance by the fact that it is a glimpse into the private life of the McCartney family at a time in the early Seventies when Paul had fled the media-fuelled madness that attended the Beatles, and by the fact that Linda is the invisible, guiding presence.
'I love that photograph,' says Mary. 'It's so weird - the dog, my brother jumping into the air, and Stella in a world of her own. I could look at it for ages. It's not set up at all; it's all about watching and timing. I bet she didn't even change the lens to take it, just used the same old 50mm lens she always did. That's what I mean about instinctive. There's a faith that it will be all right and it is. She just gets it.'
She stares at it some more, and the photographer in her gives way to the loving daughter. 'We uses to walk that fence all the time to see how far we could go before we fell off. So it has all those memories, too. Our lives are mapped out in our mum's photographs. I found out her and Dad's story just by looking through the contact sheets: her rock'n'roll stuff, then her photographs of the Beatles, then her meeting Dad. It's like her diary, really, a record of her life.'
Linda Louise Eastman began her career as a photographer almost by accident. While working as a receptionist for Town & Country magazine in Manhattan in the mid-Sixties, she picked up an invite for a press party on a boat on the Hudson. It was for the Rolling Stones, newly arrived in America. She charmed the bad boys of rock as she later charmed Hendrix and Jim Morrison.
Soon afterwards, she forsook the genteel concerns of Town & Country for the more earthy delights of the Fillmore East, a celebrated but grungy New York rock venue, where she became the house photographer, capturing live images of Bob Dylan, Janis Joplin, the Doors and the Who. Before Annie Leibovitz became Rolling Stone magazine's favourite snapper, Linda was the first woman photographer to have her work on the cover - a portrait of Eric Clapton.
'Mum liked doing music work when it was all free and easy,' Mary says, 'but when the lawyers and the accountants took over, she lost interest. She was independent always. She did it on her own terms or not at all. Plus, she had children. Children take over your life.'
Contrary to received wisdom, Linda Eastman was not an heir to the Eastman Kodak empire, but she did come from wealthy American stock. Her father Lee was a music-business attorney, while her mother, Louise Sara Lindner, inherited the Lindner department-store fortune. She died in an aeroplane crash in 1962, when Linda was just 20, precipitating in her daughter a lifelong aversion to flying.
'I think Mum and Dad were close because they both lost their mothers when they were young,' says Mary. 'It was one of the things that bonded them. You could glimpse it when certain songs came on the radio, and they'd both be suddenly sad at the same time. I also think it's what made them so family-oriented.'
Family life, one suspects, is also what grounded Paul McCartney after the craziness of the Beatles years - though blissful domesticity also seemed to soften his musical brain. For a long time Linda stopped being a professional photographer to become a musician of sorts with Wings, and had to contend with the wrath of Beatles fans who blamed her and Yoko Ono - but mostly Yoko - for the fall in quality in both Paul and John's solo work. She later admitted that she sometimes sang out of tune on early Wings songs.
Paul met Linda in the famed Bag O'Nails club in London in May 1967, where the new rock aristocracy hung out, and where she was taking shots of Georgie Fame for a feature on Swinging London. That same week, they met again when the Beatles unveiled their Sergeant Pepper album at a party in their manager Brian Epstein's Belgravia pad. In September 1968 Paul asked Linda to fly to London for a date. They married six months later. Mary was born in August 1969. On the back of her father's first solo album, McCartney, she is the curious infant peeking out of her father's jacket straight at her mother's lens.
'It's a beautiful moment, isn't it?' Mary says. Does she remember much about her childhood in Scotland? 'Oh God, yeah! I remember we'd go off exploring a lot, Stella and me, and we didn't have to be watched all the time.' It's a revealing memory, a reminder that they were still the children of one of the most famous pop stars in the world and had to be protected accordingly.
How big an influence is her mother on her own photographic style? 'I'm not sure. It was more her attitude I admired. She was feisty in her own way, but not in a big, in-your-face way. I suppose she was quietly persuasive. It took me a long time even to get to that point. I used to be so green when I started, almost apologetic. I'm more like her in the way I approach my personal projects: just me and the camera and a few rolls of film. She gave me loads of advice all the time and I really miss that, chatting and arguing over the contact sheets. I remember when I used to moan about missing a great moment, a great photograph, she'd say: "Oh, don't worry, it's in your soul camera." I think she really believed that.'
Was it hard to be the child not just of famous parents, but of parents who were seen as alternative types - hippies, vegetarians, animal rights activists? 'Well, my friend Josie used to call us hippy convoy kids,' she laughs. 'We were tomboys, that was down to Mum. She was a bit anti-authority, a bit rebellious. At the local comprehensive in Rye I tried to blend in but Mum and Dad would turn up in the Land Rover with the rainbow-stripe fabric on the seats. The rock hippy parents! I did the whole thing of being embarrassed as a teenager. I'd look at her odd stripy socks and go: "You're not going out dressed like that, Mum!" Now I think it's beautiful. Like the way she cut her own hair. It's quite cool, really.'
There is a powerful self-portrait of Linda towards the end of her life in Francis Bacon's studio. I ask Mary if this was the last image taken of her mother before she died. 'No,' she says haltingly. 'I think I took the last photographs of her. I was working on the press pictures for her cookbook. I think the very last one was a close-up where she is looking deep into the lens. Really intimate and poignant. The thing is,' she says, tears welling up, 'I don't think she ever saw it.'
As she composes herself, she sorts through the images. 'That's the thing about photographs,' she says. 'They are wonderful reminders of things, but they also carry memories, sadness.'
It must have been an emotional experience to sort through her mother's archive for the show. 'In one way it was, but in another it was satisfying. Me and Dad have a proper grown-up relationship now. I feel I was a kid for so long, but now we have both been through a lot. We're both divorcés, for a start,' she says, laughing mischievously.
Though I had been warned that the words Heather Mills were not to be even mentioned, it seemed an opportune moment to utter them. Did you, I ask, gritting my teeth, ever do a portrait of her? 'No,' she says, looking perplexed at the very thought. 'No. Not really. I didn't.'
Funny that, I say, but she does not respond. The silence, though, says enough. In more ways than one, she is her mother's daughter.
· Linda McCartney's photographs will be at the James Hyman Gallery, 5 Savile Row, London W1 (020 7494 3857) from 25 April to 19 July
