Ben Affleck (left) launched his film Hollywoodland in Venice

"More and more, people are paying attention to actors' private lives - even the mundane aspects," he said.

"Movies become commercial breaks in the soap opera of actors' lives."

He could relate to original Superman actor George Reeves, who apparently shot himself in 1959, he said. Affleck plays Reeves in new film Hollywoodland.

Speaking at the film's premiere in Venice, Affleck - known for his high-profile relationships - said he understood the perils of fame and typecasting.

Sometimes an audience can conflate an actor's life with the character he's playing Ben Affleck

"There are some things I understand about George Reeves' life because of the kind of life I have," he told reporters.

"To audiences, George was the Man of Steel. There was more to him than that and that frustrated him, and that's what I can understand," he said.

"Sometimes an audience can conflate an actor's life with the character he's playing."

Hollywoodland, which also stars Bob Hoskins, Diane Lane and Adrien Brody, centres on the investigation into Reeves's death. Reeves played Superman on TV from 1952-58.

Affleck's performance has been praised by critics and Hollywoodland has been described as his "comeback" movie after a string of underachieving films such as Jersey Girl, Daredevil and Gigli.