Comen additionally used Nuke for compositing. For the set extensions in the boxing ring, they ended up generating some CG lights and box seats up in the rafters, which were comp'd in a foggy, smoky distance. And then for shots that were actually looking down at the crowds, they repurposed some crowds from outtakes, which they stabilized and cut up into cards and placed into the background in 2.5D.

The idea with the napkin is that Ward asks Charlene Fleming (Amy Adams) for her phone number at a bar, which she gives him on napkin. It's a big moment for him and we see the napkin in close-up. "So the shot is all about this napkin, but the problem is we can't use real phone numbers on screen, so we had to change the number to something nondescript without the audience knowing this," Carras continues. "We ended up going through a couple of different takes to conceal the number. We tried masking it with motion blur and defocusing it, but that didn't work. So we ended up redesigning and re-photographing a napkin that was very strategically creased and the number was hidden in the folds of the crease and then on top of that we put in some motion blur and other stuff to finesse it so it looked believable."

There's also a sequence in which Eklund impersonates a cop and Russell wanted to play the scene so that in the beginning you don't know whether it's him or the real cop. "So they shot the night for night exterior scene of him in the headlights of a car, but it was still a little too obvious that it was Christian Bale," Carras relates. "So we went through those shots and rotoscoped out all the people in the foreground and background and then created some layers of fog and mist to make it more of an atmospheric, hazy backlit scene, and then digitally enhanced the lens flares and other artifacts off the headlights so you ended up with God's rays/projector beam of light enveloping Christian Bale in different directions. It made it so he looks like a shadowy figure for the first three or four shots of the scene. And then we dialed that down progressively through the rest of the scene until the gag becomes apparent. It helps to sell the narrative of the scene and enhance the look."

One of the trickiest parts of the scene was the roto, according to Comen. "Since we were relighting the scene, we wanted to make sure that both the roto and compositing were top notch and believable," he adds.

"Again, this isn't the kind of effects movie where you like to behave in a weird or otherworldly way -- it had to look very authentic and real," Carras concludes.

Bill Desowitz is senior editor of AWN & VFXWorld.