There’s a sizable amount of largely “invisible” visual effects work in Christopher Nolan’s Oppenheimer, but more than a month after its release, that’s still not obvious to everyone.
In the lead-up to the film, headlines spread after Nolan stated there were no computer-generated images in Oppenheimer — but that’s very different than saying there are no visual effects shots in the film.
“Some people have picked that up and taken it to mean that there are no visual effects, which is clearly not true,” Oppenheimer‘s Oscar-winning VFX supervisor Andrew Jackson tells The Hollywood Reporter. “Visual effects can encompass a whole lot of things.” That includes computer-generated imagery and “in-camera” special effects created on set.
One VFX moment is the scene re-creating the Trinity Test during in which scientists, led by J. Robert Oppenheimer (Cillian Murphy) detonated the first atomic bomb in New Mexico on July 16, 1945. According to Jackson, who won an Oscar for Nolan’s Tenet, this was done by layering filmed elements through digital compositing. In other words, the team at Nolan’s go-to VFX company DNEG took filmed images — such as smoke and explosions — and used a computer program to layer them together to create the shots. “[Nolan] didn’t want use any CG simulations of a nuclear explosion. He wanted to be in that sort of language of the era of the film … using practical filmed elements to tell that story.”
Of the visual approach to the movie, which was lensed in 65mm film with Imax cameras by cinematographer Hoyte van Hoytema, Jackson says they didn’t try to make an exact copy of what the explosion would have looked like, nor did they want something too stylized. He says they opted for something in between, “a sort of loose artistic interpretation of the ideas rather than an accurate representation of the physics.”
For the filmed elements, special effects supervisor Scott Fisher led the filming of large practical explosions and other elements with various lenses and cameras, including Imax and high-speed cameras. “They used four 44 gallon drums of fuel and then some high explosives under that, which sets the fuel alight and launches it into the air,” Jackson says of the largest practical explosions.
Ultimately, the team compiled a library of roughly 400 individual elements that it used to create the multiple layers in the compositing process.
“We had some with really close-up detail of the burning explosion,” says Jackson. “We had a lot of material that we could layer up and build into something that had the appearance of something much bigger.”
For lighting the actors in shots during which they watch the explosion from miles away, he adds, “there were some where there was a [practical] explosion in the background and other ones where we added the explosion. … Some of them had like a lighting effect on the actors for the flash as the explosion went off.” Underscoring Nolan’s love of working with film, Jackson reports that they used optical, not digital, color timing during postproduction.
In all, the film contains roughly 200 visual effects shots, including the practical effects shots. This included taking out modern elements from locations.
Jackson also acknowledged how the film’s story remains relevant today. “The subject of nuclear bombs is something that we worried about in my generation, growing up,” he says.
And on today’s thorny subject of artificial intelligence, he agrees there is a sort of similarity to the message. “We’re on the verge of a revolution in not just our industry, but across the board. I don’t think people have quite grasped the reality of how much is going to change,” he says.