Bullet-Time…With Only One Camera!
One of the most memorable innovations in the cinema in recent history that led to a complete break-through in filming was the “bullet-time” effect from The Matrix. Most of you have probably seen the scenes where this effect was used — the most notable one being the scene where Neo (Keanu Reeves) and Agent Smith (Hugo Weaving) are fighting in an underground metro station and seem to be suspended in midair as the camera rotates around them. Back in 1999, this effect was achieved by using many very expensive high-speed cameras set up around the actors. A computer would later parse and sort the frames into the memorable effect for that scene.
Even today, recreating that effect takes many cameras. Or does it? It turns out that this rotating effect can be achieved with a single camera, a ceiling fan, and a simple lighting trick. Mark Rober, a NASA engineer, figured out how to make it work without costing hundreds of thousands of dollars in expensive cameras and computer. Using the ceiling fan motor (with the blades removed), he built a platform that the motor would spin. He then mounted a GoPro camera to the edge of the platform and put up a neutral toned backdrop. Lastly were the two lights that he attached to the platform to minimize the shadow that hit the backdrop. It turns out that eliminating the shadow is the trick to making this effect work with a single camera. Without the shadow against the backdrop for reference, the eye is easily tricked into thinking that the camera is stationary and the subject of the video is spinning instead of it being the other way around.
– da Bird