Interview: Grace Robertson, photojournalist

• London Women's Pub Outing (Battersea), 1954

WHEN pioneering Scottish photojournalist Grace Robertson nervously submitted her first set of photographs to Picture Post magazine, she did so under a male pseudonym.

"I was Dick Muir," she laughs, explaining that she married the first name of a young man she had once fancied to her Glaswegian mother's maiden name. "I was rather pleased to put unrequited love to good use," she remembers. At the time, Robertson was barely 18 years old, dreaming of becoming a photojournalist for the respected magazine.

There were some major obstacles. Back in the late 1940s the majority of photographers were men. More importantly, though, Robertson was determined not to have opinions of her work focus on the fact that she was Fyfe Robertson's daughter. Her Edinburgh-born journalist father, who became a legend in his own lifetime as an idiosyncratic TV reporter with the BBC's Tonight and 24 Hours programmes, was a feature writer with Picture Post.

"I feared that being his daughter, and being female and young might all go against me," she says.

The Robertsons had never owned so much as a Box Brownie until her father, "Robbie", bought her a Leica, "as if it was the most natural thing in the world for a girl to want to become a professional photographer".

That first package of photographs was returned, although someone had written on the rejection slip: "Persevere, young man." So the "young man" did, using a cold, unused bathroom in her parents' London flat as a darkroom. Soon she had her first photo essay, about Chinese artists, published in the magazine – under her own name.

Now 79, this elegant, distinguished-looking woman, who has been garlanded with awards and honoured with an OBE for her services to photography, is astonished to discover that her work is still being collected today.

• Customers, including some eager schoolboys, buying Sweets in 1953 after rationing ended. Picture: Getty/Grace Robertson

On 20 May, a series of signed prints of some of her most iconic images will go under the hammer at Bonhams in London, with each of the four lots expected to fetch up to 800 each.

"I knew nothing at all about it until I read a paragraph in a daily newspaper saying they were being sold by a private collector," says Robertson.

She now lives in a picturesque cottage in East Sussex with her husband, Thurston Hopkins, 97, a celebrated photojournalist in his own right, with whom she has a son and daughter.

They have been married for more than five decades, after meeting while working together at Picture Post, despite the fact that he scooped her on a story about London's feral cats.

"I'm a one-man woman," she jokes, confiding that they may see eye to eye over most things but they enjoy a good argument. Hopkins's work is also featured among the 18 lots in the Bonhams sale showcasing British photojournalism in the mid-20th century. A print of one of his photographs – La Dolce Vita, Knightsbridge, London, 1950, showing a pampered poodle being chauffeured around the English capital – is expected to fetch up to 1,500.

"We had no idea someone was collecting us," says Robertson.

She says that she and her husband were privileged to belong to a generation of photographers which the Left-leaning, socially conscious Picture Post inspired and encouraged – the group also included Bert Hardy and Bill Brandt. Together they transformed the landscape of British photojournalism in the 1950s.

"Everything was complicated by the fact that England then was a country over which I felt class lay like a very wet blanket. As a Scot, I found the rejection of one class by another very hard to understand," she says.

Therefore, she felt at home at Picture Post, which ran so many features illustrating social inequalities that the magazine is credited with playing a part in developments leading to the setting up of the welfare state. During her tenure at the magazine, Robertson turned her lens on the post-war lives of women, documenting domestic details with humanity and humour.

Her photo essays ranged from a 1951 story, A Schoolgirl Does Her Homework – featuring her sister Elizabeth, then 16, who went on to a career as a singer – to a Battersea women's pub outing to Margate in 1954.

"I took any opportunity to work on stories that allowed me to meet other women," she says. When she suggested the pub outing story, it was rejected because it didn't have "broad appeal", but as soon as she submitted her photographs, the editor changed his mind. An entire issue of the magazine was devoted to women – and Robertson had the lead story. "I knew I had a winner as soon as all the pictures were printed."

In 1956, Life magazine asked her to repeat the pub outing story with women from Clapham, and it is images from both pieces – perfectly composed, artifice-free examples of classic reportage – that are being auctioned. They show comfortably rounded, well-corseted women in late middle age having a ball. Wearing their Sunday-best floral frocks and hats, they dance the conga, sup beer, flash frilly bloomers and take a ride on a big dipper. You can almost hear the raucous laughter amid a chorus of Knees Up, Mother Brown.

"It's another era, isn't it?" says Robertson. "You have to remember that these women were no longer young. They were mothers and they were all survivors of two world wars, so they were determined to have fun and a lovely picnic. They were not remotely self-conscious about it. I spent a week beforehand with them getting to know them all better, so all in all it was a very satisfying day out."

She says she can't recall ever being at a more high-spirited gathering of like-minded people who, for a few hours, gave themselves up entirely to the enjoyment of the moment. "When the party broke up and the women trailed off to their homes in small laughing and singing groups, one could only guess at a very different mood the following day," she says.

The women from Clapham "oozed a boisterousness that was quite breathtaking, and this carried the sequel to a successful conclusion". However, she could have done without Life magazine sending a Rolls-Royce Silver Cloud, complete with uniformed chauffeur, to transport her. When she told the driver she'd be travelling on the coach, he insisted on tailing them.

Life offered her associate staff membership if she moved to the United States. Recently married, the choice was between Life … and life. "I chose life," she says cheerfully.

Robertson also cherishes recollections of other assignments, such as her 1952 trip to Italy with the Bluebell Girls dance troupe, and her groundbreaking, powerful photographs of the birth of a baby – which Picture Post refused to publish lest they offend the sensibilities of middle-aged women readers. "I was furious," she says.

But one special reason for remembering the Battersea women's day-out story is that her father wrote the introductory essay. "I'd always let it be known that I'd prefer not to do assignments with Robbie – a foolishness I now deeply regret – so it was the closest we came to sharing credits," she says.

Born in Manchester – "my mother didn't make it to the Border on time" – Robertson was educated at schools all over England. "Far too many to remember," she sighs. "We were always moving because of Robbie's work."

The one constant in those austere, make-do times, though, was the school holidays, which were spent at home in Scotland, she says fondly, insisting that she's "from Edinburgh".

Growing up in an atmosphere of dedicated journalism, she always wanted to write. "But when I was 16, I had to leave school to look after my mother, Elizabeth, who was crippled with arthritis. I thought I'd die an old maid, but then my life and hers, too, was saved when she was given experimental gold injections.

"My life had changed already anyway. One day, in 1948, as I stood in the damp and drizzle in an interminable food queue, I'd noticed two women in intimate conversation, their eyes sparkling with amusement. I realised that they'd have made a marvellous photograph; I remember feeling quite breathless at the thought. Suddenly, I found myself looking – really looking for the first time. I knew that that was what I wanted to do: to take pictures like those in Picture Post."

After the magazine closed in 1957, she and Hopkins worked in advertising photography and freelanced, but she found it impossible to juggle motherhood and domesticity, so she trained as a primary school teacher.

"I used to say I didn't regret it, but now I think I do. I still lecture, exhibit and do a lots of portrait and landscape photography. Would I want to do it all again? Yes, of course … I can think of no more exciting challenge than going out, day after day, with a camera."

• The photographs sale is at Bonhams, New Bond Street, London, on 20 May.