The Lone Ranger actor, who played both Tyler and Cameron Winklevoss in the Facebook film, explained that he did not initially expect to take on both twins and struggled to switch between parts.
Hammer said in an interview with Prestige Asia: "It was much more of a technical shoot then anything else I've experienced. You're always told in acting school that it's about the emotion and the truth and all that stuff. But with this, it was more like, 'Tilt your head a little more to the left' or, 'Look over here at this tennis ball.'
"I would start as Cameron Winklevoss and we would shoot the scene until [director David] Fincher was happy, which would probably be 40 or 50 takes. Then he would say 'switch' and I would go and take off the Cameron outfit, take off the make-up, the hair and all that, and get redone as Tyler Winklevoss, remember the character of Tyler and get into that."
Hammer went on to say that there were times that he became frustrated with the process and felt close to breaking point, adding: "There were definitely some nights, when we were working late, when Fincher would say, 'You're letting the brothers bleed together. Remember what we're doing.'
"And I'm like, 'It's four in the morning and we've been doing this for 18 hours and we're on take number 1,200. Give me a break, man!'"
> Armie Hammer 'refused to shave chest for J. Edgar'
Watch the trailer for The Social Network below: