New Deal helped with this Vertigo moment that also evokes the memorable staircase in The Red Shoes.

"But it took 18 different exposures of motion picture footage stitched together from three different camera perspectives," Grossman explains. "For the foreground, we took some pretty complicated digital ash systems in Houdini that married together the whole sequence so we could control the whole shot. When she turns around, Legacy Effects built a prosthetic art piece so it could be physically art directed. We set that on a motion control turntable, shot eight passes of that with different incarnations of red light and different lighting for the environment, little pieces of practical ash and clean plates. Then we projected every single piece of that footage onto a more precise body matchmove that has every twist and turn of her waist and shoulders. And we added digital smoke and cinders and we did a digital cloth version of her dress and then seamed that all on to her digitally, and once you've got all these elements comp'd together, you've got 50 footage elements for this very brief shot."

For a Dachau flashback, they built a set in a furniture plant in Boston. But they had a tough time dealing with the frozen bodies and not making it look too real. "Marty had this image in his head," Legato recalls, "maybe he saw it in a photograph -- of the bodies being frozen and caught in mid freeze."

Meanwhile, CafeFX did a lot of work on the authenticity of the Dachau environment: controlling snow and making those piles of bodies look just right for Scorsese. "It was a very important thing," Grossman adds. "He really took that set very seriously: it had a heavy weight that he carried just because the subject matter was so heavy. It was a delicate balance with Dante Ferretti designing and redesigning those bodies, and Marty wanting us to change them quite a bit and augment them. He didn't want them to be grotesque or to cheapen the experience of a concentration camp with in your face gore and guts. He wanted to convey the minimal amount to convey the horror of the experience.

"It's always danger when you get into visual effects and you're exploring a look and that's what we had to do here, but it was more fun than usual. It's a great experience to see a filmmaker so concerned about every individual frame and there was never any shortcutting that you sometimes get in a commercial movie."

Bill Desowitz is senior editor of AWN & VFXWorld.