Here are two myths about special effects:
- They’re essentially magic tricks, useful mainly if your videos feature space ships or explosions or ghosts or car crashes and similar hotdoggy stuff.
- Like other magic tricks, they require arcane knowledge of secret techniques and long practice to master them.
Both beliefs are dead wrong.
To address the first myth, the truth is that video special effects are for everybody–so much so that you can’t make a program without them. Think about it: every time you edit two matching shots together, you’re fooling the viewer into believing that two separate actions happened continuously. That essential movie making deception is a special effect as clearly as plonking King Kong on the Empire State Building.
Secondly, you can achieve many special effects with little or no expertise. Besides, instead of learning how to set up specific tricks, it’s much more useful instead to understand the general principles that underlie those tricks and most other effects as well. By knowing what makes screen illusions possible, you’ll be able to improvise whatever particular effects your programs may require.
To help you create effects that are quick, simple, cheap, and above all, effective, we’re going to lay out three basic ideas that make video illusion feasible and then describe some fundamental techniques for getting the most out of those ideas. (For a generous collection of how-to recipes covering specific special effects, check out "Burning, Bleeding, Floating and Flying" in the September 1995 Videomaker.)
To illustrate the discussion, we’ll use an actual video project produced by beginning media-arts students.
It Doesn’t Belong in Your Face
Recently a fast-food chain ran a series of commercials based on the idea that their burgers were so drenched in delicious sauce that they dripped all over everything and every one, with predictably comic results.
A team of students decided to make one of these commercials. To push the concept to its logical extreme, they placed their slimy sauce slopper in the open cockpit of a small plane, high above a suitably terrified crowd on the ground. The storyboard lays out the commercial, redrawn by the artists at Videomaker from the students’ stick-figure original. The idea’s so simple that the board is self-explanatory, so take a moment now to scope it out.
To show just how low-tech this project was, here’s a complete inventory of the resources used to make it:
- Video: camcorder, VCR, Videonics MX1 mixer.
- Audio: CD player and sound effects disk.
- Graphics: Simple animation software and a Windows paint program, both running on an aging 486 computer.
- Sets: bulletin board painted barfo green.
- Costumes: leather helmet and jacket; white scarf.
- Props: Catsup packets, paper napkins, and discarded bun begged from school cafeteria, plus one sheet of red construction paper and some sticky tape.
- Expensive, esoteric high-tech special effects equipment: recycled cardboard and secondhand string.
You too could doubtless lay hands on old cardboard and string, and if you lack a computer and/or effects generator, bear with us anyway, because most special effects don’t need even that much technology.
With our student commercial as exhibit A, let’s demonstrate three characteristics of the video image that make special effects easy to achieve. Those key facts are:
- The image is defined by the frame around it.
- The image has only two dimensions.
- The image is too low-resolution to show fine details.
We’ll add two other crucial notions, first that the easiest special effects are not video at all, but audio, and secondly that, as in all magic, what you show is less important than what you suggest.
So let’s get started with perhaps the least understood and appreciated part of the video picture: the rectangular border that defines and limits it.
The Frame Creates the Picture
In the video universe, anything outside the picture defined by the frame around it simply doesn’t exist; and that means you can hide the machinery running most special effects simply by framing off it. (In movie jargon, "framing off" something means excluding it entirely; but "framing" something means not only including it but making it the center of the composition.)
In storyboard frame 9 the pilot’s scarf is blown backward, presumably by the wind streaming past her. Ah, but notice that the scarf tips extend beyond the image border. Because their ends are outside the magic frame, it doesn’t matter that they are tied to our secondhand string, which is being flipped up and down by an unseen student. Voila! Instant wind.
But that fake breeze doesn’t whip the "pilot’s" hair or the wrapper on her cheeseburger, so another student is standing outside the frame in front of her, flapping the used cardboard like mad to create even more wind. Because they are outside the image border, the two other students don’t exist.
Oddly enough, the exclusive frame can also have exactly the opposite effect: it can make nonexistent things seem real by suggestion. Obviously, there is no airplane, just a student standing in front of a chromakey backing (that’s what the bilious green bulletin board is for). But because the animated shot (frame 5) shows a plane, because the actor is dressed as a pilot, and because the sound track insistently features an engine, all this "evidence" convinces the viewer that the plane is really there. And because this phantom aircraft is entirely outside the magic frame, we have no way to disprove its existence.
In addition to denying off-screen things that actually do exist and suggesting other things that don’t, the magic frame performs another chore that is crucial to special effects: it tells the viewer which way is up. Unless contradicted by elements in the image–like a horizon, for instance–the vertical axis of the video world is parallel to the sides of the frame and the horizontal axis is parallel to the top and bottom.
For this reason, the pilot in storyboard frame 9 seems to have put the plane into a steep dive. In reality, the actor is standing straight, while the camcorder has been tilted sideways on its tripod. But because "vertical" is established by the side of the frame, it is the pilot who appears canted rather than the camera.
You can use the same special effect to make a person float. Position the actor with chest snug against a concrete wall that could pass for a floor and frame him in a side-view waist shot with the camera rotated a full 90 degrees to the side so that he looks like he’s lying on this "floor." Miming heavy effort, the actor simulates pushups by repeatedly pushing himself away from the wall. Then he does his pushups using only one finger and finally, he pulls his hand up off the "floor" and floats above the ground. To make the gag work, of course, you must ensure that nothing in the background gives away the fact that the camera is 90 degrees off level.
In the most spectacular use of this trick, Fred Astaire appeared to dance on the walls and ceiling of a room. To achieve this, they bolted both the room and the camera to a revolving frame and then rotated them together so that as Astaire danced toward a wall it swung horizontal to become an actual floor.
But because the camera swung with it, the wall stayed perfectly parallel to the sides of the frame and, therefore, remained a wall in the screen world although it had become a floor in the real one.
A World of Two Dimensions
The second key trait of the video world is that it has no true depth. None; zero; zippo; zilch! It’s important to pound this home because the illusion of on-screen depth is so powerful. Contrary to appearances, video people and objects that seem to be moving away from the viewer are merely growing smaller on the two-dimensional surface of the screen. The only true screen dimensions are up and down and side to side or, as animators say of their equally two-dimensional drawings, north and south and east and west.
The absence of depth makes it impossible for viewers to determine how large a screen object really is, or how far away, or, in fact, whether it is really an object at all, or merely a picture of one. That is, the fugitive third dimension takes with it the characteristics of scale, distance, and dimensionality; and that allows you to have a regular field day with special effects.
Take scale, for instance. The animated plane in frame 10 of our commercial really has no size at all (except as measured in computer screen pixels). But because it’s chromakeyed onto an actual sky background, we accept the illusion that it too is real. And since we know how big planes really are, we mentally assign it that size–a size that has no relation whatever to reality.
We could have strengthened the illusion by using a model plane instead of an animation, and one student did just that with a Lionel toy train engine. In her story, one character waves goodby to another as his train pulls away from a rural whistle stop. To achieve the illusion of a real train, she selected an open valley location without any nearby structures to show actual scale, then set her camera on the ground with the toy engine looming in the foreground and the waving actor 100 feet away.
By aligning the distant actor perfectly with the close engine, she changed a three-inch-high toy into a mighty locomotive (aided immensely by thunderous engine sound effects on the audio track). Incidentally, you need bright daylight and a wide-angle lens setting to pull off depth deceptions like this, which require sharp focus from a few inches away to infinity.
The train effect exploits the screen’s lack of any fixed scale; but it also depends on the fact that the viewer cannot perceive the actor’s true distance from the camera. In our commercial, we play tricks with distance in frames 3 and 7, in which glops of gooey sauce hurtle down from the sky.
In actual production, they hurtled nowhere. The two glops were actually free-form shapes cut from red construction paper and affixed to the green bulletin board. We framed them in wide angle as tiny spots and then made them seem to rush toward the viewer by zooming rapidly in to telephoto. Again, we enhanced the effect by chromakeying the spots onto an actual sky background.
Harking back to our "diving" pilot, notice that the falling-blob illusion also exploits the fact that the screen has no true up and down: the camera and paper splotches were aligned horizontally, although the resulting blobs seemed to fall vertically.
We can get yet another lesson from these humble splotches by noting that in the actual world they weren’t blobs at all, but only flat paper cutouts. But since the screen has only two dimensions, you can’t always tell whether or not the objects on it did or did not originally have three.
A few years back we used this trick to place a Greek temple on an empty hilltop. To achieve the effect, we carefully cut the temple out of a high-quality travel magazine photo, mounted it on a pane of glass, and aligned the cutout, the camera, and the distant hilltop so that the temple perched upon it.
Come to think of it, this effect used all three traits of the depthless screen image. The temple cutout was only two dimensional, it was only 1/100 actual scale, and, at four feet from the lens, it to appeared to perch upon a hilltop a mile away.
The Benefits of Soft and Fuzzy
The photo of the temple showed only a tiny fraction of the details of the original structure and the toy train was of course much simpler than the fire breathing monster from which it was copied.
As for the plane in our commercial, it was so schematic that its animated wings seemed broken into separate pieces by the "jaggies" effect of bitmapped diagonal lines. None of this mattered a whit because the low resolution of the video image concealed the crudeness of the model, the photo, and the animation.
Though modern engineers have achieved near miracles with our ancient NTSC format video, its images are still very coarse compared to those of still camera slides or even movie film. But the lack of detail in video images can conceal a multitude of sins, or, for special effects, cheats.
We’ve already talked about photos and models, so let’s focus on decorative elements like makeup, costumes, sets, and props.
Though believable heavy character makeup is tough to achieve even in video, you can get away with it quite successfully if your "vampire" or ten-year-old "geezer" doesn’t get too close to the camera. The same is true of costumes and accessories like jewelry, which can record quite convincingly even though it’s laughably cheesy in real life.
In the same way, rudimentary sets can look very convincing, and remember: if it’s not in the frame, it doesn’t exist. You don’t have to build a single square inch of set beyond the edge of your image.
Perhaps low resolution is kindest to props, which can be entirely believable even if they lack significant details. For instance, the bun and paper wrapper in frame 9 of our commercial were real, but the "cheeseburger" inside them was cardboard.
An even simpler prop appeared in another student production: a satire about a "zero-tolerance" high school in which students committing the tiniest infraction (like walking on the grass) are shot dead on the spot. For obvious reasons, students couldn’t go around campus firing realistic weapons, so they used camcorder batteries instead.
Yes, batteries: the skinny black bricks used in full-sized VHS camcorders, which the actors held as if they were the barrels of automatic pistols. In medium shot or longer, these stand-ins were astonishingly realistic, especially with synchronized gunshot sound effects on the audio track.
The Power of Audio
Which brings us to the cheapest and yet most effective special effect of all: audio. We "sold" the plane, the train, and the guns to viewers by supporting essentially unrealistic images with realistic sounds.
Want an earthquake? Vibrate the camcorder on its tripod as you shoot, and then lay in a thunderous rumble (subway train sounds from commercial sound effects collections work splendidly). Fire? Slowly wave a crumpled red theatrical gel in front of a light while shooting; then lay in a commercial fire noise–or simply record the crackling of the red plastic.
Audio effects are especially useful in support of our corollary that if it’s not in the frame, you can imply that it exists. Add surf sounds and gull cries to a shot of an actor with just blue sky behind and you’ve created instant beach. Let a car drive out of frame and then hold the empty image as you deliver a horrific car crash on the sound track and you’ve staged a painless and cost-free auto wreck.
To really sell that effect, I’d like to see a lone hubcap roll back into the empty frame, spin around with that distinctive "rubbedy-rubbedy-rubbedy" sound, and then slowly, dramatically come to rest on the ground.
Sound effects are easy to record, and CD collections are widely available.
Special effects are really hybrids: combinations of audio and video elements edited together to synthesize unified effects from separate components. In fact, almost all successful special effects depend heavily on skillful editing.
Editing Is Everything
Return one more time to the burger commercial and you’ll see that we created it largely through editing. For instance, we never actually see the splotch of sauce hit the man or the woman pilot a real aircraft.
In editing, the key technique is juxtaposition: the creation of an illusion by showing one piece of it after another, the way a mosaic makes a picture out of separate stones.
In the earliest days of movies, a Russian director proved this by shooting a closeup of a man looking off camera with no expression whatever. The director then edited the man’s blank look with shots of a sumptuous meal laid out on a table, a curly headed child playing happily, and a beautiful woman dead in her open coffin. Audiences marveled at the man’s amazing ability to silently convey feelings of hunger, paternal affection, and grief!
One key to selling your special effects through editing is by providing context. Notice that the commercial does not show the woman in the cockpit until very late in the story. Before she appears, we see a man searching the sky and a shot of the plane, supported by the constant drone of an aircraft engine on the sound track. By the time we finally see the woman, we accept her as a pilot in a plane, rather than an actor in front of a chromakey background.
Another key is brevity. Even the most meticulous, expensive special effects will give themselves away if they stay on screen long enough for the audience to analyze it. To prevent this, suppress your instinct to show off the effect you worked so hard on and display it just long enough to "read," as they say–to reveal what’s happening. If you need to prolong an effect for dramatic purposes, cut away from it repeatedly for reaction shots or whatever, so that even if it accumulates several seconds of screen time, it’s never visible for very long in any one shot.
Here, then, are five basic ideas behind special effects. First, use the power of the frame to exclude, to suggest, and to orient the viewer. Then, exploit the lack of three true dimensions by manipulating scale, distance, and dimensionality. Next, use the low resolution of video to conceal the artifice behind effects and always look for ways to enhance or even create the illusion through cheap, simple, and highly realistic sound. Finally, use editing to synthesize single events from a multiple shots.
Which returns us to the place where we started: the central idea that all movies are created from the ongoing special effect called editing.