Christopher Nolan has spoken of the challenges of showing an atomic explosion without resorting to computer-generated imagery for his new film, Oppenheimer.

The director’s forthcoming biopic of Robert Oppenheimer, one of the pioneers of nuclear weapons during the second world war, involves a scene recreating the first atomic detonation in New Mexico in July 1945, a month before the US dropped similar bombs on Nagasaki and Hiroshima, hastening the end of the conflict.

“Recreating the Trinity test without the use of computer graphics was a huge challenge to take on,” Nolan told Total Film.

“Andrew Jackson – my visual effects supervisor, I got him on board early on — was looking at how we could do a lot of the visual elements of the film practically, from representing quantum dynamics and quantum physics to the Trinity test itself … there were huge practical challenges.”

Nolan has long pioneered ambitious technical film-making while also mounting real-life stunts of considerable scale. He blew up a real Boeing 747 for 2020’s Tenet, flipped a truck for The Dark Knight and shot on top of melting glacier in Interstellar.

Oppenheimer stars Cillian Murphy alongside Emily Blunt, Matt Damon, Robert Downey Jr, Florence Pugh, Rami Malek and Josh Hartnett. The film will be released in July.