Comments from Spielberg about filming in 3D.
“Every movie I made, up until Tintin, I always kept one eye closed when I’ve been framing a shot,” Spielberg told me. That’s because he wanted to see the movie in 2-D, the way moviegoers would. “On Tintin, I have both of my eyes open.”
Source: 3-D: The Future of Movies – Worth a read because of the 3D technology being used for Tintin.