To maintain the rapid shooting pace Eastwood demanded, Owens chose to mostly avoid using bluescreen technology, as the process can be time-consuming and difficult to light. He instead used rotoscoping, the process whereby effects are drawn directly onto live action shots. Rotoscoping is more expensive than bluescreen, but the technique had proved reliable for Eastwood when he made extensive use of it on "Flags of Our Fathers" (2006) to avoid shooting against bluescreen on a mountaintop. For Owens, the lighting was better, and he considered rotoscoping to be "faster, easier and more natural". Owens used bluescreen in only a few locations, such as at the ends of backlot streets where it would not impact the lighting. The Universal Studios backlot had been used for so many films that Owens thought it important to disguise familiar architecture as much as possible, so some foreground and middle distance buildings were swapped. One of his favorite effects shots was a scene in which Collins exits a taxi in front of the police station. The scene was filmed almost entirely against bluescreen; only Jolie, the sidewalk, the taxi cab and an extra were real. The completed shot features the full range of effects techniques used in the film: digital extras in the foreground, set extensions, and computer-generated vehicles.