Using Kuper motion-control software, which has "an incredible array of tools that we can trick into doing just about anything," Nash figured out the rotation of the camera around a point on the bow, and then applied that circling motion to a revolving green turntable, where DiCaprio and Nucci stood at a green railing (built to match the miniature Titanic's bow) against greenscreen. "Once I figured out the geometry of it, it only took a trivial conversion of the east-west and north-south motion-control data to convert it into a north-south camera move. Then I extracted the big east-west move going around them, and translated that into the movement of the turntable. When we shot the live-action part, we used the miniature shot as a playback source on-set so we could preview the composite and see how the actors were sticking to the ship. It worked remarkably well. There's going to be a little bit of 2-D reconciliation in terms of really nailing their feet to the deck, but it was incredibly close."
There was still one more challenge to overcome before Cameron, Legato and Nash could convince audiences that DiCaprio and Nucci were actually standing on the bow of that miniature boat: lighting the actors on the rotating turntable. "They weren't supposed to be rotating relative to the world that they were in," Nash explains, "so we had to rotate the keylight with them. We hung the keylight on this horizontal arm connected to this big dinosaur vertical tower mounted on the actors' turntable."
Nash ended up shooting five of these elaborate motion-control greenscreen setups to put the talent on the miniature Titanic's deck throughout the film. The trickiest of these was a much shorter shot in which the camera rose steeply away from DiCaprio and Nucci on the bow. "It was not nearly as big a shot, but it had way more rise than I could do practically," Nash recalls. "When I shot the original moves on the miniature, I knew we'd have problems down the road shooting people to match into it, but I didn't want to tone the shot down. To shoot the live-action part, we needed to do 20' crane-arm shots, but the real-time motion-control rig we built didn't have nearly that much range. The only solution we could come up with was to put the motion-control rig way up in the air on a 60'-long, 13'-high platform and get what we could with the camera, while having the talent ride on a north-south motion-control elevator which was also on motion-control track. We took the arm of one of our motion-control rigs, built a platform on it, and basically made a rotating motion-control elevator out of it. In order to shoot this, we had some bizarre choreography involving our motion-control camera screaming down the track and craning down, with the talent rising up and rotating on a turntable coming toward camera. When we watched the shot on the videotap, it just looked like two guys against green with this stage racing by, like 'What is going on here?' But when we laid it on top of the ship, there they were standing at the bow as this big helicopter move happened. It was pretty amazing."
Framing the epic story of the Titanic's infamous journey is a "documentary" account of a salvage dive to the decomposing wreck by two small Mir submarines nearly 85 years later. DreamQuest Images had achieved similar shots of several mini-subs gliding over a sunken nuclear submarine for Cameron's previous underwater effort, The Abyss; the company's team had captured the scenes by constructing an overhead motion-control gantry, which simultaneously flew the multiple mini-sub models (mounted on wires) through the smoke-filled, dry-for-wet environment toward the downed sub set, anchored to the floor. Those shots were achieved almost entirely in-camera, which created a very believable scenario in which the mini-subs cast interactive lighting and shadows on the sunken sub set and each other.
[ continued on page 5 ]