Even Martin Scorsese has doubts about his ideas being too ambitious.

For his latest film, the Netflix gangster movie The Irishman, Scorsese had to make actors Robert De Niro, Al Pacino, and Joe Pesci look decades younger than they are using visual effects. Pulling it off--convincingly--meant relying on digital technology that hadn't yet been proven in the film industry, and that could potentially compromise the quality of a film with a reported $160 million budget. If that figure is correct, it would make The Irishman Scorese's most expensive film to date.

"It's a costly experiment, but Ted [Sarandos] and everyone at Netflix said they would go with it," Scorsese said during a press conference on Friday, the first day of the 57th-annual New York Film Festival. "They actually backed the film and financed it and were creatively attuned to us." Despite the massive budget, Scorsese said he didn't have to compromise on his creative vision for the film, as there was "no interference of any kind" from Netflix executives during production, just "some notes and things from time to time," he said.

Logistically, The Irishman represents one of Scorsese's most ambitious films, carrying a run time of just under three and a half hours. The production required shooting 309 scenes over 108 days. While it was back in 2008 when Scorsese and De Niro first declared their intention to adapt Charles Brandt's 2003 book, I Heard You Paint Houses, about a mob hitman who supposedly was involved in the death of Jimmy Hoffa, the years of waiting to make the film left Scorsese feeling emboldened rather than frustrated.

"People--as you get older--grow differently at times, and you grow separate, away from each other," he said. "This was not the case. We kept coming back." 

The decade of waiting for the project to finally start production also proved beneficial for the ways in which technological advances made the digital de-aging of the actors easier.  "The technology kept evolving; it kept changing, kept making things simpler," said producer Jane Rosenthal. The visual effects proved so convincing that, in at least one instance, Pacino didn't realize that footage of Pesci had been altered to make him look younger. 

"They showed me Joe getting out of the car and I thought, he looks great. Why does he look so good?" Pacino said during the press conference. 

Aside from the technological risks involved with the de-aging process, working with Netflix meant an added risk for Scorsese, as he couldn't guarantee the streaming company would give the movie the wide theatrical release that is typical for his films. While Netflix is releasing the movie in theaters on November 1, it will make the film available to stream less than four weeks later, on November 27, creating a much smaller window of theatrical exclusivity than Scorsese is used to. With no guarantee that he could raise the money for the film from another company, however, Scorsese decided he had to adapt to the new environment in the movie business, where getting a film made can mean partnering with a streaming company rather than a traditional studio.  

"We're in an extraordinary time of change," Scorsese said, "but when it comes down to it, ultimately Bob [De Niro] and I felt the picture had to be made." 

The Irishman screens Friday as the opening-night film of the festival.