BUSAN — Award-winning documentary filmmaker Joshua Oppenheimer talked at Dongseo University in Busan on Monday about the decade he spent making “The Act of Killing” and “The Look of Silence,” films that deal with the mass killings of suspected Communists in Indonesia in the 1960s.

Though both films have been showered with honors and festival invites, including an Oscar nod for the former and the Grand Jury Prize at this year’s Venice fest for the latter, the hardships — both financial and emotional — that Oppenheimer endured making them were still vivid in his mind as he spoke to a rapt audience. He described being turned down for funding for “The Act of Killing” and forced to cobble together production money from university grants and other sources. He talked about “being embarrassed in front of my crew for asking them to shoot more footage” when he had no idea if the film would ever see the light of day. “I thought no one might care if it spent the next 50 years under my bed,” he said.

But he kept filming and editing “The Act of Killing,” until light began to appear at the end of the tunnel in the form of Norwegian producer Signe Byrge Sorenson and other supporters. “If the film is strong, it’s not that I’m so clever, but that I kept going,” he said. His takeaway after spending 10 years living and working with the survivors of victims and the still powerful perpetrators (though one of the film’s central figures is a repentant killer): “I’ve become more forgiving. If you do something bad it doesn’t mean you are bad.” He also describes the changing Indonesian attitudes toward the killings since the release of “The Act of Killing,” which has been seen by millions in the country. “People are no longer so afraid of each other,” he said.