Dark Knight's Gotham City environments and most of the action sequences were assigned to Double Negative, which created more than half the of the 700 vfx shots. All Dark Knight images courtesy of Double Negative. ™ & © DC Comics. Courtesy of Warner Bros.

BD: Paul, what was it like working with Chris Nolan again in terms of his requirements for The Dark Knight?

Paul Franklin: It was really interesting. On the one hand, he was willing to give us a lot of creative input into shot design giving us a very loose brief and waiting to see what we came up with. On the other hand, he had learned a lot about the technology on Batman Begins and he had a very clear idea of where he wanted to take the work on The Dark Knight; not only did he challenge us to develop the high-res IMAX pipe but he also got us to do all the Scope work at 4K as opposed to 2K. In every area, he pushed the quality of the images and demanded a seamless match with the unforgiving nature of the original cinematography. However, the best thing about working on one of Chris' films is that you know that, at the end of the day, you are part of a truly great piece of filmmaking. Chris' vision for The Dark Knight lifted it way out of the genre of comic book movies and took it to a place where a vast audience responded with great enthusiasm and that's why all the vfx teams on The Dark Knight worked so hard to get the final result.

BD: Like Chris Nolan, Jon Favreau has been critical of CG. Ben, what was it like changing his perception on Iron Man?

Ben Snow: Yeah, I think that Favreau's career has gone through the history of visual effects. On Elf, he sort of had stop-motion, hanging miniatures and a lot of traditional effects techniques; and he used some of those again on Zathura, also motion control and computer graphics. But he definitely was someone who was quite critical of computer graphics being overused or not used well. And that's what it comes down to. I may be naïve, but I really think that the stigma about CG is starting to go away. People are starting to realize that it's just a toolset and how you use it is what's important. What we were able to do with the test and certainly with the film was to get it to the point where the computer graphics and the live-action suit were pretty much indistinguishable. And so we gradually moved away more and more from the brush metal silver suit and he started commenting on things that weren't CG as if they were and [vice versa].

The vfx approach on Iron Man had to first win over CG-skeptical director Jon Favreau. All Iron Man images courtesy of ILM © 2008 MVLFFLLC. ™ & © 2008 Marvel Ent. All rights reserved.

BD: So it must've been a real eye-opener for Favreau?

BS: I think so. And I have to say, to his credit, he was really great about it. And he talked about it and came up and talked to the crew and said how it really changed his perception. Obviously it's great: we love that sort of challenge and it's something we always try to do. And if you've got a director that's passionate about wanting it to look as real as possible, then you've gotta find time on the set to capture the high-dynamic-range images that might help us with the lighting, and take the time to get it right on set.

BD: It's a very tricky thing with comicbook movies, isn't it?

BS: Yeah, there was a to and fro there because we wanted to get the splash page moments, and it was almost as if Favreau was working against his better judgment: he wanted it to be real, but he knew it was important to also have these big "Iron Man is coming to punch Iron Monger" moments, with the light hitting his arm just right and a beautifully art-directed pause, which wouldn't happen if this was a real brawl. But being anchored in realism worked great.