Christopher Nolan Says He Created Look of Atomic Explosion Without CGI in 'Oppenheimer' : 'Huge Challenge'

Christopher Nolan went for practicality in the special effects used for his upcoming film Oppenheimer.

Nolan, 52, wrote and directed Universal's epic story of J. Robert Oppenheimer, the Manhattan Project mastermind who helped develop the atomic bomb, with Cillian Murphy starring as the titular scientist.

Speaking with Total Film for the outlet's upcoming 2023 Preview issue, the filmmaker said, per Games Radar, "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 explained that he brought on visual-effects supervisor Andrew Jackson "early on" in the project, and that Jackson "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," he added.

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Based on the Pulitzer Prize–winning book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and Martin J. Sherwin, the film features a large cast including Emily Blunt as Oppenheimer's wife, Katherine; Robert Downey Jr. as Lewis Strauss, a major figure in the development of nuclear weapons, according to IMDb; and Matt Damon as Lt. Gen. Leslie Groves, who oversaw the construction of the Pentagon and directed the Manhattan Project.

Murphy, 46, reunites with Nolan after previously starring in three films for the director: 2005's Batman Begins, 2010's Inception and 2017's Dunkirk.

"I'll always turn up for Chris, whatever the size of the part," Murphy told Variety in February. "Chris will call me up and I'm there. Isn't it wonderful that filmmakers are still making challenging, demanding films within the studio system, shot on film?"

"I think he's flying the flag," added the Irish actor of Nolan. "Him, Paul Thomas Anderson and Quentin Tarantino are fantastic filmmakers making interesting work on a massive scale."

Nolan told Total Film that he's "thrilled with what [his] team has been able to achieve" with Oppenheimer which, even aside from the special effects, is "a story of immense scope and scale."

"And 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," the director said. "There were big, logistical challenges, big practical challenges."

"But I had an extraordinary crew, and they really stepped up," Nolan continued. "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."

Oppenheimer is in theaters July 21, 2023.