Robert Duvall used a talk at the SXSW film festival to recall teaming up with co-stars Marlon Brando and James Caan to play pranks on director Francis Ford Copolla while shooting The Godfather.

“We’d moon each other on set,” the actor told film historian Leonard Maltin in front of a packed crowd. “Coppola didn’t mind. He knew it was important to stay loose”.

Duvall, who was nominated for an Oscar for his role as the Corleone family’s lawyer in the gangster classic, eventually won the prize in 1983. He described Brando, who died in 2004, as one of the key influences on his acting career. “He was the touchstone for my generation,” he said. “I keep a letter from him on my mantelpiece next to my Oscar. I think the letter means more.

“At his best he was the ideal. I said to him once: ‘You should have played Othello.’ He said, ‘Booooring’.”

Duvall, who was in Austin to promote his new film A Night in Old Mexico, cited Robert Altman and Ken Loach as two other film-makers who had inspired him. He remembered visiting Altman’s house while working on M*A*S*H, the director’s Palme d’Or-winning satire about the Vietnam war. Ravenously hungry, he unwittingly ate what turned out to be Altman’s young son’s sandwich. “His wife hasn’t let me forget it yet,” said Duvall.

Loach’s influence was less direct, but no less important: “Whenever I direct, I think of him,” said Duvall. “Kenneth Loach is my hero. That mixture of documentary and drama; the way he uses new actors.”

Duvall, whose credits include roles in George Lucas’s debut, THX 1138, as well as Coppola’s The Conversation and The Godfather Part II, said that it was tough to find roles as actor in his 80s.

“The pickings get a little bit scarce,” said the 83-year-old actor. “Apocalypse Now was probably the last big film I was in.”

But Duvall suggested that The Judge, a thriller in which he plays a judge suspected of murder, could be his next big hit. “They were talking about Oscars before we [even] started rehearsals,” he said. “Plus, it’s got Robert Downey Jr in it. Apparently he’s a big star now?”