Christopher Nolan revealed to Total Film magazine that he recreated the first nuclear weapon detonation without CGI effects as part of the production for his new movie “Oppenehimer.” The film stars longtime Nolan collaborator Cillian Murphy as J. Robert Oppenheimer, a leading figure of the Manhattan Project and the creation the atomic bomb during World War II. Nolan has always favored practical effects over VFX (he even blew up a real Boeing 747 for “Tenet”), so it’s no surprise he went the practical route when it came time to film a nuclear weapon explosion.

“I think recreating the Trinity test [the first nuclear weapon detonation, in New Mexico] without the use of computer graphics was a huge challenge to take on,” Nolan said. “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, to recreating, with my team, Los Alamos up on a mesa in New Mexico in extraordinary weather, a lot of which was needed for the film, in terms of the very harsh conditions out there — there were huge practical challenges.”

Nolan went on to call “Oppenheimer” a “story of immense scope and scale,” adding, “It’s one of the most challenging projects I’ve ever taken on in terms of the scale of it, and in terms of encountering the breadth of Oppenheimer’s story. There were big, logistical challenges, big practical challenges. But I had an extraordinary crew, and they really stepped up. It will be a while before we’re finished. But certainly as I watch the results come in, and as I’m putting the film together, I’m thrilled with what my team has been able to achieve.”

“Interstellar,” “Dunkirk” and “Tenet” cinematographer Hoyte van Hoytema reunited once again with Nolan for “Oppenehimer,” and the two managed to get IMAX to create a new kind of film stock for them.

“We challenged the people at Kodak and FotoKem. to make this work for us,” Nolan said. “And they stepped up. For the first time ever, we were able to shoot IMAX film in black-and-white. And the results were thrilling and extraordinary. As soon as Hoyte [van Hoytema, Nolan’s cinematographer since ‘Interstellar’] and I saw the first tests come in, we just knew that this was a format that we were immediately in love with.”

Universal Pictures is set to open “Oppenheimer” in theaters July 21, 2023.