Chris Hemsworth impressed by Robert Downey Jr

The 28-year-old Australian actor, who plays Thor in the film says he was was initially nervous about working with the "Iron Man" star, reported Contactmusic.

Chris Hemsworth and Robert Downey Jr

"He gets different reactions out of everybody. I talked to him about his preparation and how obsessive he can be at times. He said, 'You've got to be. You've got two weeks beforehand. Drill it, hours and hours and hours on end.

That's how you prepare for a scene," Hemsworth said. "It's funny because I find a lot of the time I do that, being new to this business, as a safety net for myself. You look at people like that and think, by this point in their career they must just wake up and half read the lines and do it," he added.