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Reader SurveyTrue Colors
Jun 9, 2007 1:00 PM, By Michael Goldman
A look at color grading and cinematography on Ratatouille, Shrek the Third, and Surf's Up.
One of the ongoing color issues for the Shrek franchise is the lead character's green skin: Light bounces off it and impacts characters and other imagery around him. The before/after frames pictured above illustrate some typically subtle changes.
Shrek the Third TM & © 2007 DreamWorks Animation LLC. All Rights Reserved.
It's all about the green
Much of the basic color process is the same at PDI/DreamWorks, where Shrek the Third was made. However, production designer Guillaume Areto was the main color overlord, working closely with Technicolor Digital Intermediates' Tim Peeler during the DI process to establish the final look of the digital cinema version.
A veteran of all three Shrek movies, Aretos points out that the franchise has always had an essential color problem to grapple with: The main character is green. In the world of 3D lighting, that impacts virtually everything around him.
“The issue is how to get complimentary colors and play with them, even in light and shadow, around Shrek,” Aretos says. “The problem is, when you light Shrek with a warm light — whether yellow warm or red warm — the green is extremely sensitive to it. His skin is a complex shade that reacts like the real thing would, and it is very difficult to control. He is green, and doesn't tolerate yellows very well, and the characters around him are mostly pinkish, and they don't tolerate red. So what works well for one doesn't work so well for another, and therefore, even though we light them with separate lights, some correction is still necessary at the timing stage. This was a problem with Shrek 2, which took place a lot at night, with a lot of artificial candlelight, and throughout all three movies.
“And then, when you take the whole thing to chemical film, the emulsion reacts, where the warmth of one or the other color actually pulls it into a yellow or a red, and when that happens, Shrek might look good, but the people don't, or vice versa. So there is a lot of adjustment required, and now that we can do digital color timing, we can deal with those things better.”
Aretos adds that, for the first Shrek movie, DreamWorks tried using a procedural shader developed inhouse that would have rendered an object's opposite in the color spectrum to its own light and hue.
“It turned out that it looked extremely garish and really screaming ugly,” he says with a chuckle. “So we obviously decided not to do that, and kept the same philosophy of richness in the color of light for all three movies. The problem is, to get that just right in the lab, I've practically had to live down there. Now, with the digital intermediate, we have a more efficient way to do it.”
Aretos headed up design of the color keys for Shrek the Third. “[I viewed them] like a painter really, thinking about how they will translate in 3D space,” he says. “I'm not looking for lovely flat colors that I might like. I understand that flat color is the result of key light hitting a surface, or the color of bounce light hitting the color of an object. Instead, I look at direction, intensity, hue, atmosphere — all those things. So we try to design light against the architecture of the images, just like the mental process of a painter.
“For the keys, we can't paint every shot in the movie, obviously, so we paint about eight to nine keys per each sequence on average. Some have four keys, some have 20 — it just depends. We make those detailed paintings, and then turn them over to the lighting department as their guide. Then the lighters follow my direction every day, and I take them through establishing the foundation for the shot, the direction of the light. I advise them to look at their images in black and white, so they won't be polluted by color at first. That way, they can just work on the direction and intensity of the light in black-and-white. Usually, if you have a pretty black-and-white image, it's a good foundation for the rest of it.”
Aretos directs the entire lighting process from first pass to final version, and when he says a shot is done, a “color profile” process is conducted — running the image through special LUTs to emulate the look of film. When Aretos is satisfied with those results, the imagery is sent to Peeler at Technicolor.
In the DI suite, Aretos says there was a handful of areas where filmmakers wanted to make subtle color adjustments for the digital cinema release, based on areas they felt came up short in the film version. Peeler says the DI for the digital cinema version took only about a week. That efficiency, he says, was largely due to the time and attention spent during the production of shots on continuity and time of day, in order to control the color scheme.
But, because the original, photochemical color pass didn't achieve everything filmmakers envisioned, Peeler says he was able to spend most of that time fixing flesh tones and improving depth of field in his Da Vinci 2K suite.
“A lot of sequences [originally] had to be rushed to get out the door and meet their deadlines,” he says. “There were last-minute revisions to the story that delayed things. So there were sequences where they could never get the color just right in the lab. They got it as close as possible, but Shrek's shadow detail was wrong, and the character Artie's flesh tones were too purplish, and they wanted more of an organic feel to it. In particular, the scene where they pick up Artie and head out on a boat never looked right to them. They wanted to fix it for digital cinema and the DVD, and we did that. We did some blurring work to give them more depth of field, fixed the color of Shrek's shadow, and extensive work on the boat in that scene, giving it more shadow detail. Lots of detail was lost because of how they originally put out the movie, and we put all that back in for them.”
