Earth vs. the Flying Saucers is a 1956 science fiction film directed by Fred F. Sears and starring Hugh Marlowe, Joan Taylor, , Donald Curtis, Morris Ankrum, and John Zaremba.
The special effects effects were by Ray Harryhausen.
Harryhausen designed the saucers based on a very typical comic book design. However, he animated the top section (between the dome and rim) and the bottom section (between the rim and central drop-down) so they would turn as the saucer moved. This was critical to making the flying saucers look like they were moving. Harryhausen did tests in which a simple moving saucer looked utterly fake without some sort of movement to indicate it was "working". Both moveable sections had slight cut-outs to improve the visual sensation that they were spinning and moving.
Seven flying saucers were made, varying in size from a 12-inch ship for close shots and three sets of seven-inch ships for flying in formation. The ships were made from aluminum by Harryhausen's father, Fred Harryhausen, and then anodized so they didn't reflect light.
The larger ship had a central cylinder which dropped down from the bottom. A sliding door in the cylinder served as the "door" to the ship. To create the ripple effect of the force field as the aliens left their ship, Harryhausen took a piece of rippled glass and filmed it moving in light. He matted this in, and the used a dissolve to the footage of the actors (in costume) coming out of a black door.
The smaller ships had circular panels which could be slipped open. The ray-gun was animated dropping out of the hole.
Stop-motion work requires extensive planning of each shot. Harryhausen usually drew up storyboards. But since this film used extensive shots of Washington, D.C., Harryhausen drew his saucers and movement indicators on photographs of the buildings and monuments.
Rather than create massive models of Washington, D.C., various rocket bases, forests and roads, and whatnot, Harryhausen instead animated his saucers and then used an optical printer to composite this footage with still photographs. Harryhausen realized that the saucers had to dip, change angle, rear up, and move differently all the time in order for them to seem real. He could not re-use footage, either, because audiences would quickly notice the re-used footage. So each shot was animated individually throughout the film.
Harryhausen developed a wooden brace which was suspended over his scenes. The brace contained numerous points from which thin wire was suspended. Each wire could be independently tightened to reduce its length.
The flying saucers were suspended on these wires. Their moveable parts were animated, and they were allowed to dip and wobble and turn. For these scenes, Harryhausen used his "Dynamation" technique in which he matched the light in his animated scenes with the light in the live-action footage. Dynamation also required that Harryhausen shoot about three frames of footage for every single frame of live-action footage in order for his animated ships to look real.
The climax of the film is the crashing of flying saucers into the U.S. Capitol dome, the House of Representatives, and the Washington Monument. Miniatures of each building were built. The Capitol dome and House each cost $1,500 to build, and the Washington Monument cost $500. The destruction of each building had to be planned brick-by-brick, so that the models could be destroyed brick-by-brick.
Each piece of plaster, brick, or glass that breaks loose and falls to the ground had to be animated as well. No live-action footage was used, as it could not be integrated well enough with the animated saucers. Thus, each piece of debris had to be suspended by a wire, and its movement outward/inward, its arc through the air, and its fall to the ground had to be painstakingly animated.
Afterward, live-action shots of dust and smoke were composited over the animated footage to add even more realism.
This is what a Harryhausen photographic storyboard for Earth vs. the Flying Saucers looks like:
Dynamation could be seamlessly merged with live-action footage. Harryhausen realized that even if the same brightness and whiteness of light was used on the model and the live-action, it never looked right. He did thousands of tests, and discovered that colored, brighter light worked better on small models.
He photographed his models with sections blacked out, and the live-action was then matted into these black sections. It looked incredibly seamless!
Here, in this shot, live-action smoke has also been composited in over the model of the ruined Capitol dome.
Here's Harryhausen's "aerial rig" and model of the U.S. Capitol as he films Earth vs. the Flying Saucers.
My favorite part of the film? People getting turned into goo as the Washington Monument (oddly depicted as if made out of bricks, not limestone blocks) falls on some running people.
Harryhausen was extremely upset with this segment, as the live-action footage was extremely poor while his model work was exceptionally well-filmed. They didn't match up well, because the live-action looked too grainy and unfocused.