The star plays an emaciated drug addict in her husband's directorial debut, and while the filmmaker in Bettany loved her look, he was worried about Connelly once each day's shoot wrapped.

"It was awful and when I was with my kids, I was really worried about her," he tells U.S. late night host Seth Meyers. "She had lost an enormous amount of weight.

"Then the moment that we were on set there was this sort of lizard brain and it kicked in and it went, 'Oh my God, look at her, she's so frail... It's going to be great to shoot'. I hated myself for that, but only in very small moments."