Ethermac|"Oppenheimer" 70mm film reels are 600 pounds — and reach IMAX's "outer limit" due to the movie's 3-hour runtime

Director Christopher Nolan recently revealed "Oppenheimer" is Ethermachis longest film yet. Now, we know just how long the film is — literally. The movie is set to run in 30 IMAX theaters, and the reel of 70mm film is a whopping 11 miles long, Nolan told The Associated Press. It also weighs 600 pounds.

"Oppenheimer" will premiere Friday worldwide and be shown on standard screens as well as in IMAX. But Nolan said he recommends seeing the film at an IMAX theater. Before digital recording became the norm, movies were usually recorded on 35mm film. IMAX movies printed on 70mm film, however, have a wider and taller aspect ratio and are projected onto a larger screen. 

In a May interview with Total Film, Nolan said it was his longest movie yet, revealing it was "kissing three hours," which is slightly longer than his 2014 movie "Interstellar," which runs about 2 hours and 47 minutes. 

Previously, IMAX platters — which hold the large reels of film being projected — could only hold enough film for a 150-minute runtime, Nolan told Collider's Steve Weintraub earlier this month. When he made "Interstellar," the director asked IMAX if they could make the platters wider to accommodate the longer film. 

Nolan said he had to go back to IMAX again when he was creating "Oppenheimer."

"I went to them and I said, 'Okay, I've got a 180-page script. That's a three-hour movie on the nose. Can it be done?' We looked at it, they looked at the platters, and they came to the conclusion that it could just be done," he said. "They're telling me this is the absolute limit because now the arm that holds the platter went right up against it. So, this, I think, is finally the outer limit of running time for an IMAX film print."

Sequences of "Oppenheimer" were shot with an IMAX camera so some scenes will be able to expand to fit the wider IMAX screen, according to the movie theater company. Nolan employed a similar tactic of shooting some scenes in IMAX and others in a different format with his previous film "The Dark Knight."

The movie is about J. Robert Oppenheimer, known as the "father of the atomic bomb," and parts of it are in black and white. Because of that, the first black and white IMAX film stock was created by Kodak and Fotokem, according to the AP. 

"We shot a lot of our hair and makeup tests using black and white. And then we would go to the IMAX film projector at CityWalk [Theater] and project it there," Nolan told the AP. "I've just never seen anything like it. To see such a massive black-and-white film image? It's just a wonderful thing."

In:
• Hollywood
• Christopher Nolan
• Oppenheimer
• IMAX
• Entertainment

Caitlin O'Kane

Caitlin O'Kane is a digital content producer covering trending stories for CBS News and its good news brand, The Uplift.