The show, curated by photography expert Zelda Cheatle, aims to present images that illustrate the “impact, diversity and quality of work” by AOP members since the organisation’s formation in 1968. Among the photographers with work in the show are Nadav Kander, Tim Flach, Tessa Traeger and John Claridge; with work ranging from the strange to the familiar – Duffy’s iconic Twiggy image sits alongside the photograph of the ‘pregnant man’ used in Saatchi & Saatchi’s 1970 ad for the Family Planning Association. 

One particularly striking image is that of a wild-eyed, mullet-sporting man looking directly into the lens, holding a baby with one hand and a gun with the other. Titled ‘Mike & baby, with gun. Dallas, Texas’ by Zed Nelson, the image was shot in 1997 when Nelson was working on his phonebook, Gun Nation. “I had set up a makeshift studio and Mike walked in carrying his baby. He was there to purchase ammunition for his handgun,” Nelson explains.

“I asked if I could take his picture, and he agreed. People often ask me if I posed the shot, but that’s not my style. He adopted the pose of holding the gun up in this way. To him, it was a protective gesture. He said; ‘It’s my constitutional right to own a gun and protect my family.’ Others see something very different in the picture: a pose of reckless endangerment and irresponsibility.”

The selection presents a rich range of styles, subjects and stories; showing the multifaceted way that photography can be used to educate, persuade and entertain. So celebrity portraiture is placed with hard-hitting documentation of war; painstakingly staged shots sit next to artfully captured moments of luck and surprise. 

“I was looking for a good cross section of what the Association has stood for over these many years, to represent 50 years of creativity and talent,” says Cheatle. “I began by trying to find a picture from every year but that proved to be complex and almost impossible. Some years were fertile grounds, others less so.”

She decided to curate according to decades, and eventually loosely grouped the images into Advertising, Editorial, Still Life, Portraiture, Fine Art and Landscape, and then worked to find representatives of those genres. “I believe I have chosen great pictures, with diversity and style,” she adds. 

AOP50: Images that Defined the Age runs until 1 June 2018 at the Lobby of One Canada Square, Canary Wharf, London E14