Martin Scorsese Details Working With Leonardo DiCaprio and How He's Matured as an Actor (Exclusive)

'As he changes in life, he's changing on film,' the director told ET.

Martin Scorsese loves working with Leonardo DiCaprio. ET spoke to the famed director at the New York City premiere of his latest film, Killers of the Flower Moon, and he praised the actor for his growth as an actor over the years.

"He has range. He keeps growing. He also has a lot of courage," Scorsese told ET. "I know he'll go to places that other people might pull back from... I've been working with him over the years he's been growing as a person. He's maturing from a young kid to a young man. As he changes in life, he's changing on film."

The 1920s-set crime drama, which recounts the serial killings of the Osage Nation after oil was discovered on their tribal land, also stars Robert DeNiro, with whom Scorsese has now worked 10 times. "Just hanging around together on the set," Scorsese said, is one of the perks of working with his longtime pal.

"For him to take on a character like this, there are friends of mine who saw the film and have known Bob for years... they told me after seeing the film that for the first half hour and 40 minutes they didn't realize it was Bob. And they know him!" Scorsese said with a laugh. "It's hysterical. I said, 'You must be joking.' No!  They thought it was somebody [else]."

The film premiered at Cannes in June and received a nine-minute-long standing ovation at the festival. Scorsese noted that he's "very excited by the warm reception" that the movie has received.

"I'm very excited about how the film plays tonight and how the word spreads before the picture opens," he said. "I really want [people] to see it on a big screen in a theater if you can."

Killers of the Flower Moon will hit theaters on Oct. 20 and will start streaming on Apple TV+ at a later date.