For Mark Sanger, editing "Gravity" involved a process different from that of any other film he's worked on. He cut the space adventure with director Alfonso Cuaron, employing a workflow where previsualization and computer-generated images established the structure and many cuts before a single scene was shot.

It was similar to making an animated picture, where "editing" (the story reel) comes before "shooting" (final animation).

Sanger says the limited options "promoted a new level of thinking."

Once the film's blocking was locked, he and Cuaron worked with existing footage to tighten and subtly re-sculpt scenes, instead of relying on live-action's typical coverage choices.

"For example, we had the opportunity to manipulate what happened in between leaving Ryan (Sandra Bullock) and arriving with Matt (George Clooney)," says Sanger. "That would open up a new possibility as to what that camera might do, and what lines we could play underneath.

The updated version would go to the animation team." Cuaron says, "And then the poor animators have to go and do it one more time as if you're doing take two, but changing absolutely everything."

Says Sanger: "It was a collaboration unlike any other I've known."

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