Zoptical Illusions
This essay was originally posted to Twitter between May 18, 2021 and May 30, 2021. It was composed of 1,300 words across 28 tweets.
Expensive effects-driven adventure movies can be divided into two camps: before Star Wars (Lucas, 1977) and after. Though SUPERMAN premiered after Star Wars, pre-production commenced prior, including the development of the all-important flying effects.
The strategies used on SUPERMAN were a blend of pre-existing techniques. That said, according to optical effects supervisor Roy Field, "There were many different techniques used to make Superman fly, but the best special effect of all was Christopher Reeve himself."
Field stressed that acting could make or break the plausibility of the effects: "We discovered very early on that he, being a glider pilot, could hold his body aerodynamically... [In a failed test, we] projected the image behind [a] stuntman, who had no idea how to act or fly."
With a compelling actor at their disposal, the effects team used two broad categories of techniques to create an acceptable image of a flying man in the sky. Both categories involved keeping Christopher Reeve stationary, for the most part, and building the visuals around him.
According to Roy Field, a technique called front projecton was "how the lion's share of the flying shots were photographed. This technique was supervised by Denys Coop." Reeve would hang in a harness or in gimbals, with a camera and a projector situated in front of him.
A background scene, already filmed, would be projected over Reeve, dimly enough not to show up on his skin or his costume, but brightly enough to show up on a hyper-reflective screen behind him. Reeve himself would be lit to match the lighting conditions of the background.
(This technique was also used extensively in 2001: A Space Odyssey [Kubrick, 1968], particularly in the "Dawn of Man" sequence at the beginning. This is why the leopards' eyes are glowing. The backs of their eyes, like the screen, are picking up the light of the projector.)
According to Field, "[effects supervisor] Zoran Perisic added an interesting twist to the process by synchronizing zoom lenses in the projector and the camera to allow Superman to appear to fly directly towards or away without ever moving. Zoran called this process 'zoptics.'"
Front projection greatly simplified the logistics of filming the flying scenes for the filmmakers. For more complicated shots, however, they had to content themselves with shooting Reeve in front of a blue screen, so that he could be combined with the background later.
This technique is called optical printing, or just opticals, an area of expertise for Roy Field. "Optical effects are the art of combining one, two, or many images onto one piece of film"--an actor on a blue screen, background minus an actor, runaway nuclear missiles, and so on.
Actor Marc McClure (Jimmy Olsen) explains the necessity of using this piecemeal technique for certains scene. "The blue screen technique was used when Superman needed to turn and twist in flight or become very small in the frame. The blue of the process screen is so pure..."
"...it allows itself to be photochemically removed, and for the background to replace it in the optical printer."
This technique, after a fashion, is still used today. Actors are filmed on a backdrop of pure green, which is removed digitally and replaced with visual effects.
According to Field, "The fact that Superman's costume was blue did present us with a particular problem. It was too close to the color of the blue screen. The wardrobe department had to create the costume closer to turquoise, which was different enough from the screen in color."
The filmmakers did their best to light Reeve in a way that minimized the blue in his costume, but it still looks tinted green in theatrical prints and early releases for home video and television. In the 2001 special edition, the color of the costume is corrected back to blue.
Some of the flying shots involved other actors, including Margot Kidder and Marc McClure, but a vast majority of them solely involved Reeve. His work on the flying shots continued after principal photography had already wrapped and the rest of the actors had moved on.
It must have been arduous, the amount of time Christopher Reeve spent being swung around in gimbals or dangling from a harness hidden under the trunks of his costume. (Painful, by many accounts.) The dedication he showed cannot be overstated. He allowed the movie to happen.
The timing of SUPERMAN's production deprived the effects team of the advances in special effects made by Industrial Light and Magic on Star Wars. The linchpin of ILM's groundbreaking technique was the motion control camera, which could repeat camera moves with perfect precision.
When we turn our heads, the objects in front of us move in our field of vision. Objects that are close to us move a lot. Objects that are far away, only a little. This is called parallax, which aids us with depth perception. Motion control photography simulates this effect.
If the Star Wars crew wanted to film a scene with three spaceships flying by in formation, with the Death Star in the background, the camera could film a panning shot over the Death Star, then film a shot of each spaceship, one at a time, with the exact same panning move.
(As with SUPERMAN, such shots were achieved by moving the camera around a stationary object, be it a suspended actor, a miniature model, or a piece of scenery, and allowing the camera to create the action. Moving the object itself can quickly betray mismatches in size and mass.)
Because the camera move is the same every time, each element can realistically appear together on a single piece of film, without giving away a sense of separate objects shot in separate places at separate times. The humble motion control camera makes all the difference.
If ILM were to simply eyeball each camera move--of the Death Star, and of each spaceship--there would be telltale discrepancies in the movement of those objects in relation to each other. However slight, they would ruin the illusion of parallax and erode the sense of realism.
Prior to Star Wars, this is exactly how special effects artists would have shot such a sequence. In the absence of a way of guaranteeing a uniform camera move, they just did their best, by eyeball and by intuition.
These are the conditions under which SUPERMAN was made.
The second unit team on SUPERMAN shot the moving backdrops and other background elements according to the requirements outlined in the script, without the precise coordination with the foreground elements that would have been afforded to them by the motion control camera.
This is largely the reason why there's such a difference in the quality of the special effects shots of Star Wars versus the ones in SUPERMAN. There is much more of a perceptible sense of objects suspended in front of a moving backdrop in SUPERMAN than there is in Star Wars.
Nevertheless, for my money, the special effects in SUPERMAN work wonderfully--in spite of, or, in some ways, because of their limitations. Old school special effects were never meant to be 100% photorealistic. They were never meant to literally fool our eyes and our brains.
Like hand puppets or drawings, special effects are an aid to the imagination. They illustrate the story for us, allowing us, the viewers, to complete the illusion in our mind's eye and bring the story to life. Perhaps effects are less engaging, the more they do the work for us.
Accordingly, SUPERMAN works because it's a story worth engaging with, and because its central actor does such a good job of selling his part of the illusion. It has less to do with techniques, and more to do with wanting to believe our eyes, even if only for 143 minutes.
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Published 3/9/2024
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