Once the motion of the first laser is worked out, each of the successive lasers must be animated with regard to the laser that precedes it, and whether or not it passes in front of or behind the X-wing. With the laser portion of the animation complete, the reflections that those lasers create on the T.I.E. ship which is firing them, and the X-wing which they are narrowly missing must be created. The laser beams are incredibly bright light sources. They illuminate those surfaces facing them, and cast shadows where their light is blocked from those facing surfaces. The artwork for these reflections take into consideration how many lasers appear in each frame and their distance and position relative to the ships.
We now have the artwork for the lasers, and reflections. This artwork will be photographed on five pieces of film: the color laser element which prints over the X-wing, and its matte, the color laser element which prints behind the X-wing, and its matte, and the color reflections which print over both the X-wing, and T.I.E. ship. The front, and behind color laser elements are generated by photographing back-lit, hi-contrast laser artwork in two passes. The first pass is photographed with yellow filtration, and normal exposure. This provides the hot core of the laser. The film is rewound and a second exposure of the same artwork adds the green surrounding glow. This second exposure is made through a green filter, and a—diffusion filter. The diffusion provides the soft transparency of the laser's surrounding glow. Variations in exposure are also used to help make the lasers move away with a tracer-like character. This gives us the color laser elements to go in front of and behind the X-wing. Because of the laser's transparency and because they must be printed over the X-wing and Death Star surface, mattes must be made to keep the Death Star and the X-wing from exposing the negative in the areas in which the lasers appear in the final composite. This matte is made by photographing the laser artwork in exactly the same sequence on another piece of film which will be used to eliminate exposure in the areas on the negative where the lasers must expose. This gives us the lasers in front of the X-wing, the lasers behind the X-wing and their respective mattes. The last animation element to be generated consists of the reflections of the lasers on the ship. This element is photographed on color negative through a green filter and is to be double-exposed or "burned in" during the optical composite step. It doesn't need to be seen in those areas of the ship which are lit by the key light so it needs no matte.
These elements are processed and printed for viewing the following day. Two prints are made from this color negative—one is our normal print and one is preflashed and slightly under-exposed to reduce contrast. This second print will be used in the optical printer to produce the laser and reflection effects. It has this contrast reduction to compensate for the contrast increase inherent in the optical composite step. After viewing the normal print, and checking its synchronization against the rest of the elements in the shot, this material returns to optical via Control.
While rotoscope has been generating the lasers, reflections, and garbage mattes, optical has to be assembling the rest of the elements into one of their "optical blocks". A block consists of a group of shots that have similar printing requirements. This organization of material is incredibly complex. Paul Roth has the responsibility of overseeing the assembly of these elements in workprint form and then making certain that the original negative which was conformed (cut to match ) to the workprint is accurate.
This assembly of the elements is called "line-up". In our optical process there are two phases of line-up. The first phase orients the workprints of each of the pieces of film to one another by lining up their synchronization marks. These marks are the punches that we put on the film originally at the viewer.
We now have all the elements that we have generated for this shot parallel to one another with their sync frames all in a row. If we wind this film through a synchronizer we can see everyone one of the images that must appear in each frame of the final composite, now neatly lined up in a row.
With the shot lined up in this fashion it is spliced in sync onto rolls that include elements in parallel sync for another shot of similar complexity. When several shots have been assembled onto these rolls in this fashion, these rolls become an optical block.
This block will move through all the optical composite steps as a unit. The first place that the completed workprint optical block goes, is to the negative cutter via Control. The negative cutter conforms the original eight-perforation horizontal negative to the eight-perforation workprint. We now have the optical block rolls in eight-perf workprint, and eight-perf negative. Each roll of negative is now run against each roll of workprint to insure that they match to the frame.
Each of these rolls of negative is now used to generate the optical elements that will be used to composite the shot in its final form. The blue screen elements of the T.I.E. ship and X-wing that we shot earlier will have separations made from them. The system we are using to make the mattes that isolate the ships from the background is called color difference.
Color difference is used because it is less time-consuming than blue screen composites made by conventional, three-color separations and its matte techniques. The T.I.E. ship and the X-wing separations are then used to create the hold-out matte and the window matte. These mattes will be used in the final composite step. Similar elements are generated on the Death Star surface and appropriate printing elements are made for the stars, all laser elements, the laser reflections, and the X-wing engines.
At this point, we have all the pieces of film that will have to pass through the printer to make the final composite. There are 28 pieces, not counting special garbage mattes, articulate rotoscope mattes, or the original negative from which these 28 printing elements were made.
The individual elements are distributed as follows: the T.I.E. ship and the X-wing have four color printing elements, and four mattes each. The Death Star surface has five elements: three color printing elements and two mattes. The lasers over the X-wing, and under the X-wing have two elements each: one color, and one holdout matte. The X-wing engines, and the laser reflections are single color print pieces to be double-exposed and need no matte. And lastly, the stars do not print over any other image, which means that their color printing element needs no matte of its own.
Each of the color printing elements is used to produce an exposure on the final composite negative and each of the mattes is used to keep the composite negative from being exposed in an area that will receive exposure from another element.
The matte elements are usually used in pairs. The holdout matte is a black image of the subject to be matted in on that particular frame. This black image is surrounded by clear cell. This hold-out matte is used to keep the light used to expose the final composite negative from printing any information in the area that the subject of this holdout matte will occupy in the final composite. The other element of the pair is called the window matte. This matte is used to keep the material which is in the frame with the subject of the matte from printing. In our system this matte is usually a composite of the blue screen matte with its edge gradation and the garbage matte generated in rotoscope.
This composite matte gives us a totally black frame with a hole (or window) for the subject to print through. At this point we have matte pairs for the T.I.E. ship, and X-wing, the surface, and each of the laser elements in the shot. The composite goes together much in the manner of a three dimensional jigsaw puzzle. When we applied the sync marks to the elements at the viewer we also described which element crosses over which other element. The description which optical has for this shot is as follows:
The T.I.E. ship crosses over both sets of lasers, the X-wing, the Planet, and the Stars.
The reflection element crosses over the T.I.E. ship.
The "over the X-wing lasers" cross over the X-wing, the Planet, and the Stars.
The X-wing crosses over the "Under the X-wing lasers," the Planet and the Stars.
The reflection element crosses over the X-wing.
The "Under the X-wing lasers" cross over the Planet and Stars.
The Planet crosses over the Stars.
This description determines the order in which the printing elements must be used.
Our optical printers are basically two projectors and a camera. In order to maintain the quality of our original negative through the various printing steps we combine all of our eight-perf horizontal elements through an anamorphic squeeze printing lens onto a four-perf vertical format (standard 2.35-to-1 Panavision release format). In this way, our image is only one dupe generation from the original photography.
I will describe the optical combination of this shot as simply as possible.
First we determine which image has the most other information matted over it. By starting with this piece we will use all of the holdouts of the images to be combined in this shot and remove each holdout as we prepare to insert the subject of that holdout. The holdout was providing an unexposed place on the composite negative. This will, hopefully, help to simplify the explanation, even though it may not exactly describe the way this shot will be composited. In this shot the element that has the greatest number of elements matted over it is the stars.
The stars must appear everywhere in the scene where there is no other subject. To achieve this we project the star element, (stars completely filling the negative area) onto the raw stock upon which the final composite will appear. In order to keep the stars from exposing in those areas of the composite negative where other images are to appear, we used the holdout mattes of all other elements in the shot. These mattes are put in registration with the star field we are projecting. (The hold-out matte being clear cell with a dense black image of the subject of that matte on it). The mattes of the surface, the lasers, the X-wing, and the T.I.E. ship keep the star image from exposing the composite negative by blocking the light in the exact shape and position of these subjects. We now have the latent image of a star field with perfect holes for each of the other images to print into.
We next select the element that has the next greatest number of the remaining elements printed over it. In this case, that is the surface of the Death Star. That color printing element is now projected onto the composite negative just as the stars were. Before we expose the Death Star surface onto the four-perf composite negative, the hold-out matte of the Death Star surface is removed, and the window matte of the Death Star surface is combined with the holdouts of the lasers, the X-wing, and the T.I.E. ship. The purpose of the Death Star window matte is to eliminate everything in the Death Star color printing element that we do not want to see (lights, stands, etc.). We print this combination, and now have on the composite negative the latent image of the stars and the Death Star surface, both with perfect holes for the remaining images to print into. Before continuing, we remove the window matte of the element we just printed, allowing additional images to be printed into those areas.
The step that we just performed is repeated on the laser element, the X-wing element, and the T.I.E. ship element—each time removing the hold-out matte for the color printing element that we are exposing, and inserting the window matte for that color printing element. Having completed the exposure of all the color printing elements with their appropriate matte pairs, we now have a single four-perf anamorphic negative with all of the elements of our shot printed on it—each element occupying only the space allowed for it by its mattes, and each element printed over, and under its appropriate fellow elements to achieve the proper perspective.
The print back of our composite is viewed and corrections, if any, are made. Once the composite is accepted, a print goes to editorial, the negative goes to the negative cutter via the Control department.
That is the history of one of our shots, with an average level of complexity and difficulty. There are 364 more to be completed.
