Light Iron’s Efficient Color Management for Ender’s Game
How to Support a Really Big VFX Movie from a Really Small Post House
For science-fiction fans of a certain age, the award-winning Ender's Game is a primary text. Originally published in 1985, the book about Ender Wiggin, a young tactician in Earth's war against alien invaders, became a national best-seller and spawned four direct sequels and more tie-ins. With a film verson finally in the offing, directed by Gavin Hood (X-Men Origins: Wolverine), the pressure was on to make impressive iconic imagery out of the book's war-against-the-aliens scenario.
That meant making some visual leaps — for example, the book's blank "battle room" has been re-imagined for the screen as an enormous glass dome with a breathtaking view of the earth below — and some technical ones, too. Post-production services were provided by Light Iron, which implemented a highly efficient color management system on set and in post to bring the ambitious film in on a practical budget. We spoke with Light Iron colorist (and co-founder) Ian Vertovec and CEO Michael Cioni about the challenge.
Ender's Game was Hood's first digitally shot feature, and Cioni remembers him saying that the biggest difference was the prompt arrival of dailies. "This is heresy, but it's almost like a broadcast mentality instead of a cinema mentality," Cioni explained. "You get the benefits of having constant review and feedback, which is how we do things in broadcast. The DIT, Tim Nagasawa, did incredible work, and Tim mentioned that Gavin wanted a process using our Lily Pad system on set, where he would get notes from Gavin and Don regarding the look and feel of each scene. At the end of the day, they would review everything together after it was finished processing."
One challenge was the film's shooting location — production took place in Louisiana, far from the post-production resources of Los Angeles and New York. "Normally, if you're shooting way outside of L.A., there's a disadvantage to creatives in terms of confidence checking," Cioni said. "But in a movie like this, we delivered all of the results in the field. It didn't matter that they were nowhere near a post house. We were the post house, right there in the field. They had no care that they weren't near any place that had more infrastructure."
Cioni acknowledges that a key part of getting buy-in for this process was having a director and DP who are willing to work closely with a DIT to make sure color-management tasks are completed correctly on location. And another is earning the confidence of the show's producers, who might feel it's risky to execute such a big project without traditional lab services. But he hopes the results speak for themselves. "Light Iron is a very small company, and this is a really big movie—and there was no disadvantage to the production in terms of our size," said Cioni. "Digital Domain said this was probably the smoothest VFX pipeline they've ever done. And it's interesting that it came from a small company like Light Iron and not a traditional lab."
Photo by Richard Foreman Jr., SMPSP
Starting the DI
Vertovec knew the material well, which gave him a head start in discussions with Hood. "I was a huge fan of the book from high school, when I read it for the first time," said Vertovec. "It's always been one of my favorites, and when this project came up, I re-read it because it had been so long. And I was able to pick Gavin's brain and ask him questions about how he handled certain things and solved certain problems. It was fun to talk to him on that level, and he had great insight on all that stuff."
The DI was done in July of this year, mostly under the supervision of DP Don McAlpine, ASC, ACS, who worked on the majority of the looks for the film before the final week, when the director came in for a final pass. "It's really great to get all of the more technical photographic things straightened out with the cinematographer, and then we can work with the director to take it to the next level," Vertovec says, while noting that the footage didn't present any significant challenges. "They shot this so well. It was very controlled, so we didn't really have any problems to solve beyond trying to make the images look the best they could."
Ender's Game was shot in Redcode Raw (R3D) at 5K, then debayered at full resolution before being scaled down by about half, to a 2560-pixel wide frame. The final movie frame was a standard 2K frame, which yielded a margin of about 30 percent around the edges of the image that allowed some reframing to be done and gave more information to the VFX team for motion tracking and stabilization.
"With Red, it's very straightforward," Vertovec said. "We essentially just pulled the Red log film, with a Cineon curve, from the R3D files, loaded it as 10-bit RGB in log and then colored directly into P3 color space." The DI was performed on a Quantel Pablo 4K connected to Light Iron's GenePool shared-storage system.
Photo by Richard Foreman Jr., SMPSP
Setting the Look
The look of the film grew out of the need to distinguish different environments. The military environments, where Ender is trained to wage war, were pushed toward blue, while the environment on planet Earth is much warmer. "Don and Gavin referred to it as 'a world worth saving,' so Earth is quite warm and more of a happy memory for Ender that's contrasted with his military life in command school, with very cool and strong blues. In a darker blue environment, sometimes the noise can come out a little bit. We talked about noise reduction but at the end of the day we decided it wasn't necessary. The way the camera resolved the shadow detail, we found we didn't need to render any noise reduction."
Photo courtesy of Summit Entertainment
Much of the film is set inside a space station, which poses its own challenges when it comes to depicting the passage of time and transitions between night and day. The decision to build the battle room inside a large glass sphere that made the earth, sun and stars visible gave the film a way to communicate the time of day, based on the sun's position relative to the earth and to the space station. "In the DI, we crafted a night look and a daytime look and almost like a magic-hour look for these different scenes," Vertovec said. "It opens up the film and gives it a different character than if it were just shot as an interior.
"We were discussing it and thought that perhaps the lights inside the space station would have an artificial day/night cycle, so the humans living there wouldn't feel a weird sensory deprivation. They worked this out in the lighting and then we emphasized it in the color, setting morning looks, night looks, and afternoon looks all inside the space station. The idea was that, even though it's artificially lit, there would be subliminal cues indicating the time of day."
Space Is the Place
Space itself was rendered as an especially high contrast environment, reflecting the lack of atmosphere out there. Human spaceships were given a blue light, while the alien spaceships are warmer. "You know the mosquito encased in amber from Jurassic Park?" Vertovec asks. "That was a color cue I had for a lot of the alien stuff."
Lighting the space station was a special challenge, and Vertovec crafted a look in the DI that would subtly emulate some characteristics of analog phtography. "Don and Gavin wanted the space station to be somewhat flat, and wanted to build contrast into the DI," Vertovec explained. "Rather than going more extreme in the DI, I built a luminance curve and kind of a flare effect. It's more of a highlight softness that built more contrast into the highlights—more of a flaring than a hard digital contrast. We were trying to digitally emulate what happens with some older lenses, where you can see the highlights flare into the shadows a little more. I built it with a series of luma keys and a series of blurs so the highlights glow a little bit more. It feels more organic and analog than a straight, digital, hard-contrast look."
Integration with VFX was a special challenge. The idea was to preserve the efficiencies built into the process while maintaining the color decisions made on set. That meant Digital Domain was working with R3D files, rather than uncompressed DPX sequences. "Generally—it's somewhere in the 98th percentile—VFX are done in log DPX," said Cioni. "It's a common, conservative way to work. On this film, we actually delivered Red files to Digital Domain. I have never done a major motion picture where Red files were used by a VFX company. The only exception were two David Fincher films, but their editorial team is sort of its own post house." Fincher is known for doing things his own way, but in Cioni's eyes, that's because he's one of the few filmmakers who understands how high-end post-production has been designed to work, rather than how it actually does work in practice.
"We made Red trims and uploaded those [to VFX]," Cioni continued. "They took those Red files and debayered them to EXR linear, which is the actual workflow you're supposed to use in high-end VFX. But it's not a typical workflow for a movie with 900 VFX shots. To work with those raw source files instead of DPX was another huge leap in efficiency, and lighting that raw file helped us with the color in the VFX pipeline, because they could render to match dailies. That's not something we have ever done on another film."
"They applied a color to the plate, and then to their visual effects on top of that, so the VFX color matched the plate," Vertovec said. "But in the DI, we didn't want to start with baked-in color correction, so they reversed their color corrections on the CG so that it matched the original photographic plate without the dailies color on it. It was a really interesting pipeline—we gave them R3D trims so they could comp linearly and then put Cineon encoding on their renders to deliver in log.
Photos courtesy Summit Entertainment
A New Filmmaking Model?
Cioni is eager to celebrate Ender's Game because its independent financiers include recently troubled VFX house Digital Domain, which made a bid for an ownership stake in its own work. And he says it's an example of how bigger films can be supported with smaller infrastucture than ever before. "Letting a post company of under 40 people do a 900-shot VFX movie from start to finish? That's a new concept. Nobody's going to see a small movie when they see Ender's Game. It looks like a Marvel movie, but it was made by hundreds of people instead of thousands. That is something I think the film industry, looking for financial ways to stay buoyant, can look at."
That's especially important, Cioni argued, in a world where a company like Rhythm & Hues could win an Oscar for its top-quality work at the same time that it was going out of business. "VFX studios need to leverage the value they have in big Hollywood movies," he insisted. "So do post houses—and they're next on the chopping block. We've got to change, too, or we're going to go the way of the dodo, and no one wants that. Ender's Game is an example of what the future might, potentially, be in cinema."