A Question on Traveling Mattes
Ub Iwerks received an Academy Award for his groundbreaking work on Traveling Mattes, for combining live actors and animation in Mary Poppins. Ub had worked with this since 1923, when he figured out the technique to combine Alice with her Cartoonland.
The actual 1963 camera used a beam-splitter prism to record the live actors on black on one roll of film, and the matte on another. My question: why not have both on the same roll, and eliminate the possible difference between the two rolls, like shrinkage etc.?
Having the characters and the bright yellow sodium matte area on one reel and then separating them by filtering them in an optical printer seems to be a more controlled solution. Then why split it in camera instead? Were optical printers not precise enough?
Did the colors bleed? Was it hard to separate if all was on one roll?
Anyone with a definite answer is welcome to comment!
Below three images of the retrofitted three-strip-Technicolor camera, dubbed Traveling Matte Camera #1.
First Ub with Bob Broughton, who passed away a few weeks ago, then Ub alone with the camera, and finally a shot of the open camera, the front flipped down exposing the special prism, of which there seems to have been only one, very closely guarded for many years...