Magnum Photos' 30 Under 30 competition: Rise of a new generation of narrative-documentary photographers

Lynn Rothwell, 23, says her project 'explores the idea of the ordinary becoming extraordinary through photography' (Lynn Rothwell)

David Hurn likens the esteemed Magnum photographic agency to "a family". He's been part of it since 1965, when he would get feedback from the likes of Bruce Davidson, Henri Cartier-Bresson and Elliott Erwitt. "When you come into this co-operative, you suddenly have access to people who are all better than you," he says. "That's the way to learn." And now Hurn, who was 30 when he joined the agency, is more than happy to be sharing his expertise with a new generation.

As well as setting up an influential photo-journalism course in Newport in the 1970s, he today tours colleges to give talks to students. So Hurn was an obvious candidate to help judge the inaugural 30 Under 30 competition, run by Magnum and The Photography Show alongside arts charity IdeasTap, to encourage and promote the world's best emerging talents.

The competition invited those aged 18 to 30 to submit five documentary photographs k from a narrative project. The judges were looking for "a clear storyline, technique, execution, concept and originality" in the work – and the 30 winning entries are currently on show at the Photography Show in Birmingham.

The final 30 form a notably international bunch; the five featured here hail from Iran to Venezuela, the UK to Ukraine. "Some of the photographs that I think are the best come from countries where it's rather brave that they're even photographing at all," says Hurn.

Not that he prioritised political or social issues while judging. "What I look for is authorship," he says – "somebody [whose] pictures don't look like anybody else's pictures. Most people take lots of pictures, which you see on Facebook – thousands and thousands of pictures – but they could have been taken by anybody.

"Also, I love pictures of people who cry, or laugh, or show some kind of emotion – I'm not in the least interested in walls or peeling paint, which seems to be what people are taught to do nowadays." But the Magnum cache impressed k on this front: "There were lots of people in this group who seemed to be interested in the fact that human beings relate to each other, and that that is an interesting thing to look at and glorify."

Although now a veteran, Hurn wants the industry to pay more attention to emerging photographers. When he was still in his twenties, he was photographing everything from the Hungarian Revolution to The Beatles and James Bond. Such early success is now rare – though why, in an era when we so fetishise youthful talent, is a mystery. "It's about time that we k went back to the days when we didn't think that young photographers had to be 36," he says. "Everything has got older now, which puzzles me – especially when one thinks that the first Magnum photographers were all in the agency by the time they were 24 or 25."

30 Under 30 is run by The Photography Show and Magnum Photos. Pictures from all 30 photographers are being displayed at The Photography Show until Tuesday at Birmingham NEC (photographyshow.com)