Integrated Team Effort

Lighting

Most notably, all three supervisors come from photographic backgrounds, and their knowledge of cameras and lighting is reflected in each of the nominated films. “The technology is now here to do incredibly accurate lighting,” says Fink, a previous Oscar nominee for Batman Returns and this year's Achievement in Visual Effects winner for The Golden Compass. “That's where the art is.”

Integrating effects within a film's photographic style is their key concern. Knoll, whose work on the Pirates franchise has earned him three Oscar nominations and last year's statuette, says he believes that lighting is crucial to making effects blend with the look created by a DP. “We pick up where the DP leaves off,” says Knoll, who began his ILM career as a cameraman. Although he's computer savvy (he co-authored the original Adobe Photoshop), Knoll sees advantages in having a live-action background. “Experiences on set, like holding a light meter and figuring out how to do an exposure split, teach you where the tradeoffs are. It helps you avoid mistakes like having interiors at the same brightness as exteriors,” he says. Supervisors having only CG backgrounds can be vulnerable to such errors, Knoll says. “For example, the standard cameras in animation systems rotate around their nodal centers. And that almost never happens in the real world.”

Transformers provides a striking example of live-action approaches to illuminating visual effects. Farrar, an Oscar winner for Cocoon, approached Transformers by imagining how a DP would have photographed 20ft.-tall robots if they really could stride through a shot. “If they were really on set, they'd be lit separately when they're in closer view,” he says. “The DP would knock out the sunlight for the close-ups and have HMIs [Hydrargyrum medium-arc iodide lamps] and cutters to cause shadows. You wouldn't just be worried about rendering the background lighting. Of course you need to reflect the background, and we recorded the robots' environments with reflective spheres — that's a given. But we totally relit the robots to look great wherever they were.” To accomplish this, ILM created virtual versions of cutters, flags, bounce cards, and shiny boards. “The robots could move in and out of shadows, which generally isn't done much in computer-graphics lighting,” Farrar says.


Camerawork

This year's nominees also demonstrated that locked-off visual-effects shots are increasingly rare. “We try to conform stylistically to the rest of the movie,” Knoll says. “Pirates was never shot from static cameras, so we didn't want the visual effects to take on a different look. You don't want to feel like you've entered a part of the movie that was heavily storyboarded. … The state of the art has advanced to the point where you can kind of not worry about the camera. Tracking software has become more sophisticated, and crews have developed very good methodologies for solving complex camera motion. We don't think twice about Steadicam or handheld shots. That makes for better shots, because it's impressive when you see CG happening in the background of a Steadicam shot.”

That is not to say that current tracking methods have become standardized, however. For The Golden Compass, shots were shared by several facilities — including Framestore CFC, Rhythm & Hues, Cinesite, Digital Domain, Tippett Studio, and Rainmaker. “Everyone does it differently,” Fink says. “When a background would go to another facility, it would be re-tracked. There's very little sharing of motion data. Of course, these facilities were usually tracking different parts of the frame.”

In Transformers, where the camera moved rapidly through cityscapes, Farrar employed photogrammetry to create backgrounds racing by. “It's a photoreal movie, so we photographed as many real buildings as possible. When we used computer models, the textural information was actual photography. We'd hang a camera over a street and photograph it in all directions. There were shots where a camera was flying down the street, and the shot was assembled from still photos. We'd relight it and add interesting shadows and maybe even change the colors of buildings to make it more appealing,” Farrar says.

source: http://digitalcontentproducer.com/mil/features/video_integrated_team_effort/index.html