Damien Chazelle says the real-life story behind 'First Man' is more "wild and shocking" than he could've imagined.

Damien Chazelle

Damien Chazelle

The 33-year-old director has helmed the new movie about Neil Armstrong, the astronaut who became the first man to walk on the Moon, and Damien has revealed that his pre-shoot research led him to discovery lots of new and surprising things about the American icon.

He explained: "I think it was really important that it be as authentic as possible. That's why it was such a joy to work with someone like Josh [Singer, the screenwriter], because he just goes into the research to an extent ... and gets so OCD and obsessive about the research that ... No, but it just grounds everything.

"We kept finding stuff in the research that was more sort of wild and shocking and emotional and informative than stuff we could have come up with anyway."

The movie is based on the book 'First Man: The Life of Neil A. Armstrong' by James R. Hansen.

And Damien admits he was fortunate to be able to lean on some of Neil's family and former colleagues for advice throughout the filming process.

He told Collider: "We were really lucky to have those doors open to us and spend some real, quality time with these people and often have them come to the set. So we could just make sure that we got every ... you know down to the nitty-gritty, that we could try to get it as accurate as we could."