Filmmaker Christopher Nolan describes the challenges of creating "The Odyssey": "It should be hard"

Filmmaker Christopher Nolan said he knew filming "The Odyssey," which was shot in six countries, "was going to be hard.""For us, it was just the sheer magnitude of it's 'The Odyssey,' it should be hard.We're going to go out there and we're going to make it as well as we can," Nolan told "CBS Mornings" co-host Gayle King in an interview that aired on Monday."The Odyssey," which Nolan wrote and directed, pulled in more than $260 million worldwide over the weekend.

It features a star-studded cast, including Matt Damon, Anne Hathaway, Zendaya and Tom Holland."It was the hardest movie definitely that I've ever done," Damon told "CBS Mornings" recently."It felt in a lot of ways more like an expedition than a movie because of the locations we were at.

We'd be shooting on top of a mountain.We'd have to hike up the mountain to shoot and that part of it ended up being really fun because it was challenging, for everybody there."The film is also the first commercial feature shot entirely in IMAX.Nolan said he told himself as a teenager that if he ever had the opportunity to direct a Hollywood film, he wanted "to do the whole thing on IMAX.""It immerses you.

The image is so sharp, the color is so clear.It's so much the way your eyes see the world," he said.

"It fills your peripheral vision when it's on the biggest screen possible." But it comes with more challenges."The film is huge.… So after each, sort of just under three minutes, you run out of film," Nolan explained.

"So you have to ask the actors on a longer scene to just stay in the emotional state that they're in, however intense that is, and then you quietly reload the camera and keep everybody focused and then start the scene again."For Nolan, authenticity in the film was key."These are great actors.You could stick them in front of a green screen and they'd do amazing," he said.

"But to me, for the audience, if you want to put the audience on the deck of that ship, get out there on a real boat w...