Bringing this ambitious and dark vision to the screen was an enormous challenge for production company DNA Films and visual-effects house Prime Focus, especially given that the film, written by Alex Garland (28 Days Later) and shot by acclaimed DP Anthony Dod Mantle (Slumdog Millionaire), was made on a reported budget of just $45 million—and filmed in 3D.Because so little had been shot in 3D in Britain when preproduction began two years ago, the team went to Post Republic in Berlin, "as they had supplied the digilab services on StreetDance 3D, the only 3D film out in Europe then that had not been made in the States," reports Clare St. John, postproduction supervisor at DNA. "And we had a lot less money than most of the other big 3D films out there."
Dredd was shot entirely in South Africa and The Post Republic set up a digilab at Cape Town Studios. All the 3D footage was processed there, and Jon Thum, the visual-effects supervisor for Prime Focus and the film, also went there to set up shop. "The idea was to turn over early vfx shots, to follow on with the early pre-vis work we had done," reports St. John. "And once filming was complete, the digilab was shipped back to Berlin, so we had a continuity of technicians. They already knew the material and some of the problems that were inherent to 3D. And the DP is very experimental and he also developed a small handheld camera rig for close-ups."
The temporary 3D Avid cutting room in Cape Town was also shipped back to London. "So we serviced the production from Berlin, and all the visual effects were done in London—most of them at Prime who had worked with us all the way through concept design and preproduction," she adds. "We had to turn over visual-effects shots early on, especially to get the big CG shots done, so our visual-effects editor would order up the shots and The Post Republic would supply the raw data to Prime Focus." Establishing this workflow took "some working out," reveals St. John, "but we got there in the end."
Thum first came aboard two years ago, "when it was just the producers and writer on board," he recalls. "We started pre-vis, design and concept work here at Prime. And considering it was a lower-budget film for all the ambitious visual effects they wanted, we tried to approach it all in a different way." This included setting up a vfx department inside Prime Focus from scratch, specifically to do Dredd. "As we were so involved in the original design work, we could develop our assets alongside the concepts and also advise on the best way to shoot the film, including finding suitable locations," he notes.