In pictures: Iain Macmillan - The Scot who shot the Sixties

• Iain Macmillan's portrait of John Lennon and Yoko Ono

You might imagine that a photographer such as David Bailey was behind the camera when these captivating images were taken.

Instead, it was Iain Macmillan, a lesser-known Dundee photographer, whose body of work includes one of the most famous photographs ever taken – the one on the cover of the Beatles' 1969 Abbey Road album, showing John, Paul, George and Ringo striding over a zebra crossing.

These images, and about a thousand others, are owned by a close friend of the photographer, who promised Macmillan, before the artist died of lung cancer in 2006, that he would organise an exhibition of his work in his home town. A cross-section of photographs from the collection has now been loaned to Dundee's Discovery Point gallery, where a retrospective, From Dundee to Abbey Road, will be on show from today until 3 June.

Staff at the gallery jumped at the chance of exhibiting these historic images, but only after the penny had dropped as to who this not-so-familiar name was.

"I got a phone call out of the blue one day. It was someone asking if we'd like to hold an exhibition featuring the work of Iain Macmillan and, I have to admit, I went blank," says Gill Poulter, exhibitions and museums director at Discovery Point. "But the more that the person on the phone told me about this photographer, the more I couldn't believe that I'd never heard of him. Particularly as he's a son of Dundee, the city in which I work."

Poulter, with the help of the owner of these photographs, who wants to remain anonymous, shortlisted 40 that she thought would have broad appeal. There's enough in the collection for several exhibitions, though, so they had to be ruthless. Other John and Yoko, David Frost and Ivor Cutler portraits, missed the final cut.

Some of the images that were selected include Macmillan's earlier work, taken after his graduation from Regent Street Polytechnic in the late 1950s. Many of these shots feature social commentary images of Dundee tenements. Despite the fact that the photographer was middle-class (his father worked in insurance), it seems that he was drawn to poorer areas, where he took the reportage-style pictures that led to commissions from the likes of the Sunday Times and Illustrated London News.

• A dapper crowd in Carnaby Street, London

"He recorded everyday scenes with such a sense of sympathy," says Poulter. "In some of the shots of children playing in the back-greens his subjects seem to be unaware of his presence, which makes them look very natural."

You may wonder how a Tayside boy made the transition from this kind of social realism to taking pictures of the London glitterati. We can thank Yoko Ono for that. She commissioned Macmillan to document her 1966 solo exhibition at the Indica Gallery, after he'd photographed her for the art section of The Book of London (published in 1967) – a pictorial record of life in the city, a copy of which will also be on display at Discovery Point. It was at the opening of her show that Ono met Lennon, with Macmillan finding himself at the centre of a historic popular culture encounter.

His friendship with the couple resulted in many images. He was commissioned to create the covers for Ono and Lennon's collaborative tracks, including Live Peace in Toronto, Sometime in New York City and Happy Xmas (War is Over). The most important shot, however, has to be the Abbey Road photograph (of which there are six versions on display, in a cabinet at Discovery Point), which was snapped beside the EMI Studios, from Macmillan's vantage point at the top of a ladder.

"Nobody knows, when they take a picture, that it's going to become one of the world's most iconic images," says Poulter. "He had ten minutes to take that shot and, as he only took six images, he had to hope that he'd got something good in the bag."

That image, which was all over the world's news media yet again this month when EMI decided to put the historic studio up for sale, will be a draw for many of those who'll visit this exhibition. However, if you're interested in the human story of a man at the heart of the Swinging Sixties, who also photographed Brian Jones of the Rolling Stones, Bridget Riley and Pete Townshend, check out the self-portrait of Macmillan, resplendent in the insouciantly cool uniform of black jeans and polo-neck ("He always smoked French cigarettes," adds Poulter).

There will also be archive material on display, including the photographer's Hasselblad and Nikon cameras, handmade Christmas cards received from Yoko Ono, plus invitations to parties and events – including some from Paul and Linda McCartney, who were great friends and supporters of Macmillan.

• Dundee youngsters drink their milk

Contrary to the impression that mementoes such as these might create, people who knew the artist say he was not part of the London party circuit. He was never impressed by celebrity and preferred to take the commissions, do his job, then go home.

In fact, in the mid 1970s, he dropped out of the scene altogether, moving to Stoke-on-Trent to teach photography, later returning home to his birthplace of Carnoustie, where he unobtrusively lived out his days.

"From what I gather he was an incredibly modest man and that's part of the reason he's not well-known," says Poulter. "You could be friends with him for ten years and he wouldn't tell you about his work.

"He dropped out quite early, as I think it was all a bit too much for him. His agent explained that Iain was too gentle for the business. He wasn't hard enough for all the knocks, so he got out. But he's left an incredible body of work behind."

He hasn't been forgotten by his good friend Yoko Ono either. As she says; "I am so glad that Iain is getting some recognition. He was an incredible photographer."

From Dundee to Abbey Road: The Photographs of Iain Macmillan is at Discovery Point, Discovery Quay, Dundee (01382 309060, www.rrsdiscovery.com), until 3 June. Admission free.

This article was originally published in The Scotsman on 27 February 2010