NEW YORK — Christopher Nolan has never been one to take the easy or straightforward route while making a movie.

Unique Filmmaking Approach

He shoots on large-format film with large, cumbersome cameras to get the best possible cinematic image. He prefers practical effects over computer-generated ones and real locations over soundstages — even when that means recreating an atomic explosion in the harsh winds of the New Mexico desert in the middle of the night for “Oppenheimer,” out July 21.

Though, despite internet rumors, they did not detonate an actual nuclear weapon.

And as for the biography that inspired his newest film, Kai Bird and Martin J. Sherwin’s riveting, linear narrative “American Prometheus” was simply the starting point from which Nolan crafted a beguiling labyrinth of suspense and drama.

Success in Hollywood

It’s why, in his two decades working in Hollywood, Nolan has become a franchise unto himself — the rare auteur writer-director who makes films that are both intellectually stimulating and commercial, accounting for more than $5 billion in box office receipts. That combination is part of the reason why he’s able to attract Oscar winners and movie stars not just to headline his films, but also to turn out for just a scene or two.

“We’ve all been so intoxicated by his films,” said Emily Blunt, who plays J. Robert Oppenheimer’s wife, Kitty. “That exploration of huge themes in an entertaining way doesn’t happen. It just doesn’t happen. That depth, the depth of the material, and yet on this massive epic scale.”

The Complex Story of Oppenheimer

In the vast and complex story of the brilliant theoretical physicist who oversaw the Manhattan Project and the development of the atomic bomb during World War II, Nolan saw exciting possibilities to play with genre and form. There was the race to develop it before the Germans did, espionage, romance, domestic turmoil, a courtroom drama, bruised egos, political machinations, communist panic, and the burden of having created something that could destroy the world.

And then there was the man himself, beloved by most but hated by enough, who, after achieving icon status in American society, saw his reputation and sense of self annihilated by the very institutions that built him.

“It’s such an ambitious story to tell,” said Matt Damon, who plays Gen. Leslie Groves Jr. “Reading the script, I had the same feeling I had when I read ‘Interstellar,’ which was: ‘This is great. How the hell is he going to do this?’”

It’s not so disconnected from Nolan’s other films, either. As critic Tom Shone noted in his book about the director, “Looked at one way, Nolan’s films are all allegories of men who first find their salvation in structure only to find themselves betrayed or engulfed by it.”

Nolan turned to Cillian Murphy to take on the gargantuan task of portraying Oppenheimer. Murphy had already acted in five Nolan films, including the Batman trilogy, “Dunkirk” and “Inception,” but this would be his first time as a lead — something he had secretly pined for.

“You feel a responsibility, but then a great hunger and excitement to try and do it, to see where you can get,” said Murphy, who prepped extensively for six months before filming, working closely with Nolan throughout. “It was an awful lot of work, but I loved it. There is this kind of frisson, this energy when you’re on a Chris Nolan set about the potential for what you’re going to achieve.”

It would be an all-consuming role that would require some physical transformation to approximate that famously thin silhouette. A complex, contradictory figure, Oppenheimer emerged from a somewhat awkward youth to become a renaissance man who seemed to carry equal passion for the Bhagavad Gita, Proust, physics, languages, New Mexico, philosophical questions about disarmament and the perfectly mixed martini. But Murphy knew he was in safe hands with Nolan.

“He’s the most natural director I’ve ever worked with. And the notes that he gives to an actor, are quite remarkable. How he can gently bring you to a different place with your performance is quite stunning in such a subtle, low-key, understated way,” Murphy said. “It can have a profound effect on the way you look at a scene from one take to another take.”

Two Different Timelines in the Film

Nolan wrote the main timeline of the film in the first person, to represent Oppenheimer’s subjective experience.

“We want to see everything through Oppenheimer’s point of view,” Nolan said. “That’s a huge challenge for an actor to take on because they’re having to worry about the performance, the truth of the performance, but also make sure that that’s always open to the audience.”

The other timeline, filmed in black and white, is more objective and focused on Lewis Strauss (Robert Downey Jr.), a founding member of the Atomic Energy Commission and a supporter of the development of the more destructive hydrogen bomb.

“Oppenheimer” is Nolan’s first R-rated film since 2002’s “Insomnia,” which after years of working exclusively in PG-13, he’s comfortable with. It fits the gravity of the material.

“We’re dealing with the most serious and adult story you could imagine — very important, dramatic events that changed the world and defined the world we live in today,” Nolan said. “You don’t want to compromise in any way.”

Filmed in New Mexico

Much of the filming took place in New Mexico, including at the real Los Alamos laboratory where thousands of scientists, technicians and their families lived and worked for two years in the effort to develop the bomb. Nolan enlisted many of his frequent behind-the-scenes collaborators, including his wife and producer Emma Thomas, cinematographer Hoyte Van Hoytema, composer Ludwig Göransson and special effects supervisors Scott Fisher and Andrew Jackson, as well as some newcomers like production designer Ruth de Jong and costume designer Ellen Mirojnick to help bring this world to life.

“It was a very focused set — fun set as well, not too serious. But the work was serious, the sweating of the details was serious,” Blunt said. “Everyone needs to kind of match Chris’ excellence, or want to.”

Recreating the Trinity Test

When it came to recreating the Trinity test, Oppenheimer’s chosen name for the first nuclear detonation, art and life blended in a visceral way.

“We wanted to put the audience there in that bunker,” Nolan said. “That meant really trying to make these things as beautiful and frightening and awe inspiring as they would have been to the people at the time.”

Though no real nukes were used, they did stage a lot of real explosions to approximate the blindingly bright atomic fire and mushroom cloud.

“To do those safely in a real environment out in the nighttime desert, there’s a degree of discipline and focus and adrenaline and just executing that for the film that echoes and mirrors what these guys went through on the grandest scale in a really interesting way,” Nolan said. “I felt everybody had that very, very tight sense of tension and focus around all those shooting nights.”

The weather also “did what it needed to do, as per history,” Murphy said, as the wind picked up and whipped around the set.

“I’m rumored to be very lucky with the weather and it’s not the case. It’s just that we decide to shoot whatever the weather,” Nolan said. “In the case of the Trinity test, it was essential, central to the story that this big storm rolls in with tremendous drama. And it did. That really made the sequence come to life.”

He added: “The extremity of it put me very much in the mindset of what it must have been like for these guys. It really felt like we were out in it.”

The Experience of Watching ‘Oppenheimer’

Then, of course, there is the experience of watching “Oppenheimer.”

“When you’re making a movie, I feel like you’re on the inside looking out,” Blunt said. “It’s really overwhelming to see it reflected back at you, especially one of this magnitude. … I just felt like my breastplate was going to shatter, it was so intense.”

The hope is that when “Oppenheimer” is unleashed on the world, audiences will be as invested and will seek it out on the biggest screen they can find. The film has a run in IMAX theaters around the country, not something often afforded serious-minded, R-rated movies in the middle of the busy summer season. But this is also the essential Nolan impossibility. As more and more auteurs have had to compromise — to either go smaller or team with streamers to get the kind of budget they might once have had at studios, like even Ridley Scott and Martin Scorsese have had to do this year — Nolan continues to make his movies on the grandest scale.

“Each of his films has been revolutionary in their own way,” Murphy said. “It’s an event every time he releases a film, and rightly so.”