How Christopher Nolan Blew Up the Screen: The Making of ‘Oppenheimer’

Contrary to all those clearly erroneous fan rumors, Christopher Nolan obviously did not detonate an atomic bomb while making the historical epic Oppenheimer. 

To re-create the Trinity Test — the world’s first A-bomb explosion — he and his team fired off tons of TNT, set flame to gallons of gasoline, and burned up mountains of magnesium and aluminum powder. But the 53-year-old director, famous for his preference for practical effects over computer-generated ones — this, remember, is the guy who crashed a real Boeing 747 while shooting his 2020 thriller Tenet — drew the line at nuclear fusion.

“It’s gallows humor, a very dark joke,” Nolan says with a laugh about those fan rumors that he was planning on setting off an actual nuclear blast in the New Mexico desert. “It made me feel that polar responsibility to leave no doubt as to the seriousness of atomic munitions and the magnitude of change they brought to the world.”

The story of J. Robert Oppenheimer, the so-called father of the atomic bomb — played by longtime Nolan collaborator Cillian Murphy, with Emily Blunt portraying his wife and a troupe of other A-listers like Robert Downey Jr., Florence Pugh, Matt Damon and Josh Hartnett filling out the rest of the cast — is one that Nolan has been contemplating for some time. “I grew up in the United Kingdom in the ’80s, where there was this really intense focus on the threat of nuclear weapons,” he says. “That’s where my interest in Oppenheimer originates.”

Adds producer and Nolan’s wife, Emma Thomas, “In Tenet, there’s a reference to Oppenheimer, and I think the story of the movie and the story of the man speaks to many of the themes in Chris’ movies and his preoccupations in terms of technological advances and how they interact with the personal story.” 

Producer Chuck Roven, with whom Thomas and Nolan produced the Dark Knight trilogy, suggested the book American Prometheus, a biography of the famed physicist by Kai Bird and Martin J. Sherwin, to Nolan and it seemed “like kismet that it fell into our lap in that way,” says Thomas. 

Nolan wrote the script in just a couple of months, basing much of it on material gleaned from American Prometheus as well as other research. But the thing that took him the most time, he says, was the idea of the first-person narrative (this is Nolan’s first film in that perspective) and diving into the Senate confirmation hearing transcripts that revealed “David Hill as a figure in the climax of the story.” When he was done, he handed the pages to Thomas to read, then to visual effects supervisor Andrew Jackson, who won an Oscar for his work on Nolan’s Tenet.

“I went to him right away and I said, ‘Yes, there are not that many shots in here … but taking on this subject matter — the first nuclear explosion but also all the visualizations of atomic theory and quantum behavior that have to feel like a piece of a whole in a very, very analog film — can we do so without CG?’ ” Nolan explains. “Andrew told me he needed privacy and the ability to work on his own for a long time, months and months in advance, just trying things, experimenting.” Then, Jackson collaborated with special effects supervisor Scott Fisher to finesse the Trinity Test sequences. Nolan notes that visual effects are usually done in post, while special effects are on the ground, and he often pushes the two departments to work together on his films. “Andrew is just a wizard with these analog effects,” he says. “I knew he’d be able to do it if he had enough time.”

Nearly all of Nolan’s films since 2002’s Insomnia have been released by Warner Bros. — The Prestige being the one exception, and Paramount released Interstellar domestically — but this time he decided to shop around for a new partner. A strong proponent of the theatrical experience, Nolan had been miffed by Warners’ decision in 2020, in the midst of the pandemic and theater closings, to put its entire 2021 theatrical slate on its newly rebranded streaming service, HBO Max (now Max). 

Not surprisingly, Universal jumped at the chance to work with Nolan, giving him a reported $100 million budget. “He makes films that are undeniably theatrical,” Universal Pictures chair Donna Langley said at SXSW in 2022, adding at CinemaCon 2023 that there “simply isn’t another filmmaker whose commitment to protecting and supporting theatrical is more steadfast.”

Nolan’s next move was to assemble his team of actors with casting director John Papsidera, starting with Murphy. “As he always does, Chris called me out of the blue — or, rather, Emma called me and passed the phone over to Chris because he doesn’t possess one — and he said in his very understated British way, ‘I’m making a new film, it’s about J. Robert Oppenheimer, and I’d like you to play Oppenheimer,’ ” says the actor. “I said yes before I read the script.” 

Downey, who plays Oppenheimer’s nemesis, former acting U.S. Secretary of Commerce Lewis Strauss, did read the script before taking the part but didn’t need any more convincing than Murphy. “I thought, ‘If this is anything like it reads, it’s going to be bananas,’ ” he says. “From the first 30 seconds, you’re just like, ‘Whoa!’ You’re strapping in and getting ready for the blastoff.”

As per usual on Nolan’s movies, his screenplay was shrouded in Manhattan Project-like secrecy, printed on red paper to prevent photocopying and leaks (something the filmmaker has done since the Batman films). Blunt went to Nolan’s house to read the script in his library. “I would have said yes if he wanted me to play a janitor,” she says.

Principal photography began in February 2022, with Hoyte van Hoytema serving as cinematographer. Although 85 days had been allocated for the shoot, Nolan shortened it to 57 to free up more of the budget for production designs and location shooting. One of the most expansive sets was a re-creation of Los Alamos, the makeshift town where Oppenheimer and his team of scientists raced to beat the Germans and the Russians in creating the A-bomb. Because the actual Los Alamos had drastically changed from the collection of shacks, laboratories and cottages that were constructed for the mission during the 1940s, production designer Ruth De Jong and her team set about rebuilding the original town on top of a dusty mesa near Ghost Ranch, New Mexico, in the middle of winter, which brought about its own challenges.

“The U.S. government gave [the Manhattan Project] $2 billion, three to four years and an Army Corps of Engineers to build the original Los Alamos,” De Jong says. “I had [none of that].” 

Adds Nolan: “We went up to visit the set right before Christmas, and there was a terrible storm when we were up there … all the Portaloos and other construction stuff had been blown over, and there was blue ice everywhere. You were barely able to dig holes in the ground at that time of year. Ruth and her crew had two months to get the whole thing built, and they did an incredible job.” 

Meanwhile, as the sets were being erected, Nolan, Thomas and van Hoytema had been working with Kodak, FotoKem, Imax and Panavision on a whole different sort of technological breakthrough. In the film, scenes from Oppenheimer’s point of view are shown in color, shot in large-format 65 mm, while those viewed from Strauss’ perspective are black-and-white, also shot on 65 mm. Except, before Oppenheimer, 65 mm black-and-white film didn’t exist.

“There’s never been a demand for 65 mm black-and-white film — no one had ever shot large format black-and-white, and in particular, no one had ever shot Imax black-and-white,” says Nolan. The filmmaker and cinematographer asked Kodak and FotoKem to manufacture a black-and-white film stock specifically for the movie, which van Hoytema says forced Imax and Panavision to reengineer their cameras to accommodate the new film. “It was quite a big operation,” van Hoytema notes. 

There was an option to shoot the black-and-white sequences on 35 mm, but van Hoytema thought alternating between 65 mm and 35 mm would have made the latter sequences look too raw or grainy. 

“Even though it was one of the most logistically complex [parts of the production], you always knew that if it didn’t work, you had a fallback position because you could shoot it and digitize it and take the color out of it,” adds Nolan. “[But] I would really not have been happy to do that. It would have been a great disappointment to Hoyte or myself to do that.” 

The use of Imax cameras also enhanced the intimacy of the story in the sense that van Hoytema shot faces very up close and personal. “I knew that it would be highly subjective storytelling, and I knew Chris wanted us to be in Oppenheimer’s head and that he wanted to use the Imax camera for very intimate scenes,” says Murphy. “I figured out fairly early that it would have to be quite an interior, small performance.”

While the filmmakers say that no CG was used in the film, some digital magic was used to enhance practical effects. Ahead of the film’s release, news outlets reported that Nolan wasn’t using any CG to film the explosion, leading many to falsely speculate that he set off a real atomic bomb in the middle of the New Mexico desert. But just because Nolan said there would be no CG, doesn’t mean that there would not be any VFX shots. The two are not interchangeable.

“No one ever said there was no visual effects,” Jackson says. “The visual effects were based on photographic material rather than completely computer generated, so there’s always a photographic base to the visual effects work.” 

For example, that scene where the plutonium bullet slides down a tube toward the center of the bomb? Jackson and Fisher figured out how to practically shoot that effect by sliding items down pieces of scaffolding tube and filming them with lights trained on the ends. No computer effects were added — that setup is used in the film. And the quantum particle and wave sequences also were fashioned through “high school-like projects,” using metal dropping onto cold plates or rotating ping-pong balls, says van Hoytema. “Everything you see is generated by physical matter of physical things that are shot.” Then van Hoytema used a “snorkel lens” to get inside this “micro experience and film it relatively wide.” Most members of the filmmaking crew tell THR that the atom sequences were the most challenging on the film.

For the Trinity Test — the film’s money shot — Jackson’s team created a full-scale model of the metal globe-like bomb. “We needed to see it in the lab being assembled, and we needed to see it at Trinity being hoisted up in the tower,” Fisher explains. But Nolan’s crew also worked with “bigatures,” reduced-scaled replicas that were more manageable to film around. The actual Trinity tower, for instance, stood 110 feet tall; the one in the movie reached only about 30 feet. The real mushroom cloud explosion that was set off in 1944 was miles high, but the one Nolan ignited for the film reached only a few hundred feet. The practical effect was enhanced and made to feel larger by slowing down the film and layering composites over it — some of them had 100 layers of images. Van Hoytema then accentuated the shots with lighting, like strobe lights.

“Chris wants to do everything practical for the sake of it, but I really believe in the difference of quality in doing things practically versus doing things on CG,” van Hoytema explains.  

No CG was deployed to age and de-age Murphy, either. Instead, makeup artist Luisa Abel used old-school tricks to change the actor’s appearance. Abel tells THR that for Oppenheimer’s youngest looks, she had plumpers made to create youthful fullness, accentuated by highlight and shadow. A natural makeup look brought out Murphy’s freckles, and Abel darkened his brows. For his older looks, she used her custom aging stipple mix, purposefully made for the Imax format, and added depth and highlight with light washes of color. Minute details, like nicotine stains on his fingertips from smoking, also were added. For his final look, where he receives an award from President Lyndon B. Johnson, she applied full silicone pieces in the neck, cheek, nasal labial and under the eye. 

Murphy lost an undisclosed amount of weight over six months to portray Oppenheimer and grew and cut his hair multiple times during production to match the character’s appearance at different stages of life. No wigs were worn during filming, and shooting days somewhat revolved around Murphy’s hair length. Costume designer Ellen Mirojnick and her team sourced vintage wristwatches, wedding rings, belt buckles and other accessories to keep the film’s wardrobe looking authentic (although Oppenheimer’s cigarettes were fake herbal smokes). David Bowie in his Thin White Duke era was an inspiration for Oppenheimer’s look for Nolan and Mirojnick. But the wide-brim porkpie hat that was such a signature part of Oppenheimer’s look was surprisingly difficult to find. 

“I was getting more and more nervous because it’s such an iconic thing — it’s like when we did the Dark Knight trilogy and we had to figure out the Batsuit,” says Nolan. Adds Mirojnick: “It’s a hybrid of a hat. I’ve not seen it elsewhere.”

The shoot itself, often bedeviled by weather difficulties in the New Mexican desert, was particularly challenging for Murphy, who was shot for nearly every scene of the three-hour movie, except for the Lewis Strauss courtroom scenes. “It was incredibly hard and taxing,” he says. “It was like a fever dream that I just went through and was kind of spat out the other end because I was just so immersed in the whole thing, to the point where you cancel real life completely.”

In the end, though, Oppenheimer went off with a bang: The film has grossed nearly $1 billion at the box office since it was released July 21, the very same day that Nolan’s former studio, Warner Bros., put Barbie in theaters. The resulting chain reaction ignited the cultural boom known as Barbenheimer, with moviegoers taking in both movies on the same day in a coast-to-coast, black-and-white meets pink double feature. The two films’ combined opening weekend box office was an explosive $246 million.

This story first appeared in the Jan. 10 issue of The Hollywood Reporter magazine. Click here to subscribe.