James Franco and Zachary Quinto ribbed and praised their I Am Michael director, newcomer Justin Kelly, during an interview about the ambitious new film, which just premiered at Sundance. Speaking with Rolling Stone film critic Peter Travers, the trio talked about the film’s roots, the experience making it and the reaction it garnered from the real Michael Glatze, a former gay rights activist turned evangelical Christian pastor.

Franco, who plays Glatze, explained the story first came to his attention when executive producer Gus Van Sant sent him a link to Benoit Denizet-Lewis’ 2011 New York Times Magazine article “My Ex-Gay Friend.” The article detailed Glatze’s rise within the gay rights movement, as well as his spiritual crisis, conversion and ultimate split from his lover and the gay community as a whole — a story Van Sant believed could make a great movie.

“At first I thought, ‘You think this would make a great movie, Gus? I don’t know,'” Franco remembered with a laugh. “But I just kind of went on faith. We kept going with it…Gus recommended Justin [to direct], who had been an assistant editor on Milk and saw all my nude scenes from Milk in detail — he still has them!”

I Am Michael marks Kelly’s full-length feature debut as a director, and Quinto praised him for establishing a collaborative spirit right from the beginning. “It permeated the whole journey that we took together,” he said. “He didn’t have to max out his credit cards, but it’s not like people were throwing money at him and giving him free rein; we were working under some pretty some serious constraints at the time.”

As for the real Michael Glatze’s reaction to the film, all three were pleased — if not somewhat surprised — to say that he thoroughly enjoyed it. “He came up to each of us and said, ‘Thank you,'” Franco said. “I guess we did the whole experience justice.”