For Cameron, Cirque du Soleil Worlds Away "was a dream come true. I had been talking to them for some time about doing something in 3D because it's never been done. How lucky to be working with the Cirque du Soleil family, to have that talent create such an emotional performance for this film. Because their death-defying acts require such incredible skill and nerve, we felt it was so important to show the cabling, everything supporting that human ability.

"We were working with a different stage crew every four days. We did use the live shows and shot both during the live performances and on their dark days. It was cost effective to shoot during the live shows, but we did get the best stuff on dark days because we were able to come in from different angles. We dropped in with our 10 3D cameras and started shooting. But it's a lot different than just standing back with a ring of cameras and shooting a live show.

We were getting in there with the Steadicam, shooting close-ups — in their faces as close as possible — getting into the action because it's much better for 3D. I lobbied for high camera positions so when you are shooting down you get that sense of vertigo. At times we were shooting from 50 to 100 feet in the air, and you feel the height of these amazing artists performing 90 feet above the floor. You also realize the jeopardy they are in all the time. "The live experience of these shows is incredible. But in the movie theater, what we can give you is the experience of being right in the middle of a show where you will really get to see the detailed work that's gone into the characters, the costumes and the choreography. There is pageantry to the live experience, but there is an intimacy to the 3D experience."

One of the challenges for the filmmakers of Cirque du Soleil Worlds Away was that 3D involves more complicated cameras and technology and thus more time to set up the equipment. Prep also meant meeting strict safety parameters with underwater cameras (avoiding the lethal mix of electricity and water) and camera cranes (out of harm's way of aerialists and flying objects.) "There was a lot of hurry up and wait," notes producer Martin Bolduc, "which is difficult for Cirque du Soleil performers as their bodies are cooling off and they need a minimum of time to warm up their muscles after a certain period of inactivity."

Still, the shooting schedule was relatively short — 37 days over three time periods: October-November 2010 in Las Vegas, December 2011 in New Zealand and February 2011 again in Vegas. The only CGI used in the film are scenes in the desert when Mia and the Aerialist travel between the tents. "Twice a day, five days a week the performers do their work," says Cameron. "When we told them we would make a 3D film that would really capture their commitment to their art, I don't think these artists really knew what to expect. They were a bit jaded because they do it day after day, year after year. But when it was over and they saw what they do through our eyes they were awestruck. It rejuvenated them."