Oscar-winning actress Sandra Bullock revealed she relished loneliness for her latest film Gravity as the movie screened at the BFI London Film Festival.
The 49-year-old, who stars in Alfonso Cuaron's sci-fi adventure with George Clooney, spent a lot of her time alone on screen as medical engineer Dr Ryan Stone, who is stranded in space after the shuttle is destroyed.
The mother-of-one admitted it was very lonely on set "every day when they left me alone for 10 hours at a time".
"They (the cast and crew) would go off for lunch and I'd be in there. I think they had a lot of lunches," she quipped.
"But it was worth it. It was the way it was supposed to be. Had it been easy and comfortable, it wouldn't have been appropriate," she added.
Bullock flashed her legs in a black lace Stella McCartney mini-dress and Charlotte Olympia heels, despite the chilly weather at the UK premiere in London's West End. At one point, she told the crowds off for being too noisy as she did interviews on the red carpet but later signed autographs and posed for photographs.
She said the Mexican filmmaker persuaded her to join on, after years of delays. Angelina Jolie, Natalie Portman, Scarlett Johansson and Blake Lively were previously linked to the role.
"I think this is a new genre. It's an emotional story told using elements of sci-fi and action with the technical aspects available now," she explained.
Cuaron was full of praise for his leading lady, who won the best actress Oscar for her performance in The Blind Side.
"I always knew the amazing truthfulness she brings to a performance but I was not prepared for her amazing discipline and precision," he revealed.
"She prepared for five months for this role because she was performing under the worst conditions. Sandra was performing against nothing and everything was just make-believe. How she delivered it was absolutely spectacular."
Gravity will be released in 3D on Friday, November 8.
The 57th BFI London Film Festival in partnership with American Express runs until Sunday, October 20.