Cinesite's most important contribution to Road to Perdition was an effects shot that marks a crucial thematic transition. The shot lasts about 40 seconds and seamlessly marries two separate locations in Chicago. It begins on Hanks' character, Michael Sullivan, whom we see through a car windshield as he drives into the city; his son is sleeping in the back seat, and Lake Michigan passes by in the background. Reflections of the city's buildings play on the outside of the car window, and the boy, partially obscured by them, awakens and sees the city for the first time. The car has been traveling from the countryside, and the boy's face is filled with wonder and awe at the skyscrapers that have materialized outside the car. Meanwhile, the camera continues to pass along the side of the car. As the auto pulls away, the camera cranes up to reveal the LaSalle Street bridge, perfectly framed by the canyon-like cityscape beyond.
Most viewers will not realize that the scene is an effects shot, but this reveal of the period city required both high technology and many hours of painstaking effort. "Sam Mendes really loved the way the canyon looked," says Mike McAlister, visual-effects supervisor on Road to Perdition. "The trouble was that on LaSalle Street, the background looking in the other direction for the first part of the shot was really boring, so they couldn't do the shot for real. The second location, on Belbow Street, made for a more interesting background and also made the transition from open space to the city more dramatic. Our challenge was to figure out a way to get this shot without compromising Conrad Hall's lighting and without taking a whole lot of time."
The live-action portion of the shot was done at the LaSalle Street location. For the first part of the shot, the car was rocked gently, but was not moving forward. The vehicle's windows were lined with tracing paper that would later be replaced digitally. There were no glass windows in the car, partly because they would have reflected the camera and crane. Some of the tracing paper had to be ripped off during the shot to reveal the desired backgrounds when they became visible.
The camera was placed on a Technocrane mounted on dolly track. The car invisibly transitions from its standing position to motion as the boy's face wipes through frame. The Technocrane accelerates as the car picks up speed, simultaneously extending its arm in a carefully choreographed ballet. Once the camera and the car are at the same speed, the crane slows down to make it look as though the car is pulling away. The illusion, aided by some digitally added camera shake, is that the car has been moving all along.
Once the shot reaches the point where the camera is behind the car, we are fully on the LaSalle Street location. Cinesite then added the proper reflections and backgrounds to the windows, replacing the tracing paper. For the LaSalle Street location, certain modern buildings, streetlights and street markings were replaced or eliminated. To make the shot pristine, a construction project was removed from the frame, and an El train, flying birds and light shards were added.
Mendes put McAlister in charge of choreographing the shot, which was carefully rehearsed for an afternoon and then executed in half an hour. Cinesite compositor Ted Andre also played a key role. "Earlier, I had driven around Chicago with the show's production designer, Dennis Gassner," says McAlister. "We looked at all of the locations that had a chance of working. I took stills in different positions, and then used Photoshop to work out all of the complicated perspective and lighting issues involved in blending two locations. That told me exactly where to put my camera on LaSalle Street, and exactly where to put it at the Belbow location, so that all of the perspective issues would work out."
A 180-degree background from the Belbow Street location was necessary. "I knew we wouldn't be able to do any sort of meaningful motion-control work because we were shooting both locations on the same day, and there wouldn't be enough time to rig the equipment at both locations," says McAlister. "Instead, I set up three cameras in a panoramic situation, with overlap between three different images, and we stitched all three shots together. We motion-tracked the camera movement as it circled the car, and then used that information to animate the background so that the view outside the windows of the car was always in the proper perspective."
The various building-reflection elements were shot with long lenses and skewed slightly to give them a more imposing feel. The final shot, which is approximately 1,100 frames long, shows the car passing the park, the buildings reflected in the windows, and the car crossing the LaSalle Street bridge into the city, and it looks as though it was one long take filmed at one location.
"The scene is supposed to feel like Dorothy's arrival into Oz," says McAlister. "It's fun to work on a shot that's so crucial to the story. This shot tells the story without a word of dialogue or any explanation, which I really enjoy. Technically, the scene was a real brain-stretcher. But when you're working with someone like Conrad Hall, who is such a great artist when it comes to lighting, choreography and composition, the last thing you want to do is encumber him by, say, bringing in a giant greenscreen. What makes this type of work interesting is finding a way to absorb some of the logistical complications through the use of effect techniques. That's how visual effects should be done."