4. Special Effects
You know youve done something right when James Cameron says youve made the greatest space film of all time, and whether its a spaceship blowing up, tethers getting tangled around collapsing structures, the 3D that isnt tacked on, or any other spectacularly crafted sequence, its hard to watch without constant enthusiasm, wondering just how all of these marvelous feats were achieved. I actually researched some things and have something to show you, too.
"Alfonso Cuarón, cinematographer Emmanuel Lubezki, and visual effects supervisor Tim Webber decided that they couldn't make Gravity as they wanted to by simply using traditional methods. So for the spacewalk scenes, says Webber, "We decided to shoot (the actors') faces and create everything else digitally. Which was quite a difficult decision." To do that, Lubezki reasoned, he would need to light the faces to match the all-digital environment they'd be put into. Whether the characters were floating gently, changing direction or tumbling in space, the facial light would have to be a perfect match for the Earth, sun and stars in the background. "That can break easily," explains Lubezki, "if the light is not moving at the speed that it has to move, if the position of the light is not right, if the contrast or density on the faces is wrong, et cetera." Lubezki suggested folding an LED screen into a box, putting the actor inside, and using the light from the screen to light the actor. That way, instead of moving either Bullock or Clooney in the middle of static lights, the projected image could move while they stayed still and safe. This "light box" became the key to the spacewalk scenes. But it was only a nine-foot cube, just big enough for one actor, not an actor and a camera crew."