Director Quentin Tarantino sought the advice of acting icon Sidney Poitier before starting to shoot Django Unchained because he was "uncomfortable" about re-enacting the slave scenes with black actors whose ancestors suffered the same fate.

The filmmaker admits he had never before experienced the wave of doubt he felt as he imagined having to bring his story to life, instructing a hundred extras to march, in chains, on a former plantation field in Louisiana, where much of the western was filmed.

He explains, "There was only one thing I felt uncomfortable about in the beginning stages of finishing the script. It's one thing to write about a slave auction town where 100 slaves walked through deep s**t mud in chains wearing metal collars. This whole town was almost like a Black Auschwitz. It's one thing to write but to get 100 black folks, put 'em in chains and march them through the mud and putting an army of black folks dressed as slaves in the hot sun picking cotton... I started to question if I could do it and I don't think I've ever thought that when it came to my work before.

"I thought of maybe shooting those sequences in the West Indies where they have their own issues of slavery, but since this is an American story there would be a once removed quality. My problem was having Americans do those scenes. I was trying to get around it to escape the pain."

Tarantino consulted his pal Poitier, the first black actor to win an Academy Award, and the veteran star immediately told him he had to face up to his fears for the sake of his own movie - and the local economy: "I went out to dinner with Sidney Poitier who is like a father figure and was explaining my scheme of escaping. He basically told me I had to man up, 'For whatever reason you were born to tell this story and you need to not be afraid of your own movie. You just need to do it. Everybody knows what time it is. Just treat the actors with love and respect, not atmosphere and it'll all be good. By the way those people in the South need money, they need jobs. You gotta do it.'

"There were a lot of extras who were like, 'I was a slave in (Steven Spielberg's) Abraham Lincoln (movie) and I'm a slave in this. I'm good with that!'"

Meanwhile, actress Kerry Washington insists she was drawn to play Jamie Foxx's wife Broomhilda Von Shaft because the western was different from other slave movies she had ever seen.

She says, "In the past, people might have felt nervous playing a slave because so many narratives on television about slavery are about helplessness. This is about a black man who finds his freedom and rescues his wife. I was very moved by the love story, particularly in a time when slaves weren't allowed to fall in love and get married. I told Quentin I want to do this movie for my father because he grew up in a world where there were no black superheroes and that's what this movie is."

And Leonardo DiCaprio, who portrays ruthless plantation owner Calvin Candie, hopes the new film will prompt fresh discussions and examinations about America's past as a slave nation: "It's a sore subject matter that should be looked at more often and not shied away from. As daring as it is, I commend Quentin for making the movie entertaining for an audience."