In 1995 the restoration of the Star Wars Trilogy began. One of the main things that needed to be done was the restoration of the film. During the 20 years since it was last shown the optical quality of the movie had declined more than anyone thought it would. In the unrestored film Darth Vader was no longer black, but a greenish-blue. To correct this problem they had to physically wash the whole negative. This was done by a team of film restoreationists, who then realized that the opticals couldn't be washed because the dirt was built into the elements. This meant that they had to be recomposited. In the original film optical technology was used to do the composites. This method requires film technicians to physically handle the negative, leading to wear and tear, and dirt on the final product.
Now compositing is done with computers. Before the images could be recomposited
the original elements had to be located. After most movies all of these objects would be
thrown away. But George kept them so that they would have the ability to redo the
In The Empire Strikes Back The Snow Battle was a technical challenge. In the
original film the elements were optically composited. One of the problems with this is that it
leaves a black line at the edge of the object that was composited. This was easy to eliminate
in Star Wars where the back ground was the blacknes of space. But in the snow battle ,
against a white back ground, this was not as easy. To eliminate the black line the
technicians didn't print all the elements at their full opacity. So scenery is visible thought
parts of the cockpit that you couldn't normally see. In the Special Edition, the technicians
were able to use computers to do the compositing, and were able to eliminate the
transparency of the cockpit and other objects.
In all of the Trilogy, George Lucas wanted things to look a certain way, though this
was often impossible with models on wires. The disadvantages of models on wires is that
they can't be seen from multiple angles underneath, and moving with them is slow and
awkward. So they redid those shots with computers.
In the Return of the Jedi, Jabaa the Hut is a large mechanical slug that took six operators. There is an introduction to Java in Star Wars but not as a slug. Because of time they used a stand in character that would be replaced by a stop motion puppet. In the special Edition when they did add the slug with computers and not with a puppet it took about a year.