The British leads of Mandela: Long Walk to Freedom feared the worst when the audience at the authorised biopic's Johannesburg premiere, last November, sat in stony silence for the entire film.
"In Toronto there had been a standing ovation that went on for eight minutes, and people were really vocal," recalled Naomie Harris, the 37-year-old Londoner who plays anti-apartheid firebrand Winnie Mandela (now Winnie Madikizela-Mandela) when I met her, Justin Chadwick, the film's British director and Idris Elba, who plays Nelson Mandela, in London. "So I was like 'Oh my gosh, they don't like it'."
When the lights went up, the mood suddenly changed. "One of the Mandela nieces was in my arms, sobbing; and Winnie was in tears. I realised that they were processing it on a profound level," she said.
Her first meeting with Mandela's controversial ex-wife had also been nerve-racking. By that point, the actress had thoroughly researched Winnie - which included watching rare 16mm film of her after leaving prison for the first time, having endured 17 months in solitary confinement - and built up a picture of a pretty formidable woman. "So it was really scary to sit down with her," she said.
"She must be the only actor playing Winnie Mandela to have the guts to actually sit with Winnie Mandela and talk to her," Chadwick said.
Harris admitted that they didn't connect the first time they met but said they had done since. "She didn't really know anything about me and was just a bit dubious, as I would be, I think. But she is really happy with the film as a whole and how she is portrayed."
When we met, everyone was conscious that Mandela was lying sick at home in Johannesburg but still hoped that he would be well enough one day to see the film. The following night, however, as the cast and director attended a Royal gala screening in Leicester Square, news spread that the ailing 95-year-old had died. In the end, he saw only excerpts.
Chadwick recalled taking Mandela, who was about to turn 94, an iPad loaded with 200 images from his extraordinary life, as a present on the previous evening.
"I sat next to him and he was razor-sharp in terms of who was in the pictures, where they were taken, the dates, times, everything," the director said, adding that Mandela remained well while the movie was being shot. "So I was gutted that just as I was getting to the point of making the director's cut, he became very, very ill. I'm just honoured that I made the film when he was alive, because this is his account."
The lavish drama is based on the late freedom fighter-turned-politician's 1995 memoir, and charts his life from boyhood through his early struggles against apartheid, and years in prison - 18 out of 27 of which were spent on Robben Island - to his inauguration as the first democratically elected president of South Africa. To focus the narrative, Chadwick and the producers decided to make his fight against white rule and the toll it took on his family the spine of the film.
There was a lot of material, and they had to be selective about what they included. "But we can still be true to the man we're representing," Chadwick said. "We can see him as a young man. We can see him as a dad . . . You have a perception about Mandela as a great leader and a great-grandfather figure, and this icon but who would have known that he was a boxer? Who would have known that he liked fast cars and women and clothes and tailoring?"
Chadwick thought early on that Mandela's family and their associates might try to steer the project in an entirely favourable direction but no one, including Winnie, asked to see the script.
Some still claim that he has made a hagiography but the filmmaker argues passionately that this isn't the case.
"The complicated thing is it's not a reverential take. We show Mandela's flawed character. We show the controversial side (up to a point) of Winnie Mandela's character. We show the good and the bad in the film."
Indeed, because the events that took place in Mandela's lifetime were so well documented by filmmakers as they were happening, Chadwick felt he had to be truthful at all times, despite making "massive leaps in terms of storytelling". To try and accomplish this, he forged relationships with communities where the struggle had happened and, dismissing concerns over safety, shot in poverty-stricken townships among people who had lived through - and were still living with the legacy of - the events they were depicting. The wounds made by apartheid are still raw and emotions would sometimes boil over.
"I wouldn't have wanted to be a white police officer in the film when you're in the middle of Soweto where the struggle is very much part of everyday life today," Chadwick said. "We were using real people that had lived it. So sometimes cars would go up or tyres would be lit or thrown."
The film needed to be shot in South Africa, Harris said, because of the historical truth in "people's eyes when you're re-enacting situations and giving speeches. They're moved in a way that you wouldn't find in Kenya", where she and Chadwick shot their previous collaboration, The First Grader.
Elba, inevitably, felt under pressure. Local crew members knew him from his acclaimed performance as the drug dealer Stringer Bell in The Wire but they questioned whether he could embody Mandela. By the end, he'd won them over.
He said: "I just remember everybody being in tears when we were showing them clips of what we've done, and it was, like, a very genuine moment because they were like 'You did it, man. I feel like I've been watching him'. At that point I was like 'I don't care if the critics love this film or not . . . they've told me we've done it'."