Once a person puts on a cloak made with retro-reflective material (high-tech fabric covered with thousands and thousands of small beads that bounce light back exactly in the same direction from which it came — and very brightly) here’s the sequence of events:
- A digital video camera captures the scene behind the person wearing the cloak.
- The computer processes the captured image and makes the calculations necessary to adjust the still image or video so it will look realistic when it is projected.
- The projector receives the enhanced image from the computer and shines the image through a pinhole-sized opening onto the combiner.
- The silvered half of the mirror, which is completely reflective, bounces the projected image toward the person wearing the cloak.
- The cloak acts like a movie screen, reflecting light directly back to the source, which in this case is the mirror.
- Light rays bouncing off the cloak pass through the transparent part of the mirror and fall on the user’s eyes. Remember that the light rays bouncing off the cloak contain the image of the scene that exists behind the person wearing the cloak.
The person wearing the cloak appears invisible because the background scene is being displayed onto the retro-reflective material. At the same time, light rays from the rest of the world are allowed to reach the user’s eye, making it seem as if an invisible person exists in an otherwise normal-looking world.
