Ex-NASA Engineer Creates Matrix-Style Bullet-Time Effect

By Joelle Renstrom | 7 years ago

If you’ve ever seen the Matrix (and honestly, who among you hasn’t?), you’ve likely marveled at the special effects, particularly when the Wachowskis appear to stop time during some of the fighting sequences. Mark Rober, who used to be a Jet Propulsion Laboratory engineer for NASA, figured out how to “stop time” using a ceiling fan, a couple of flashlights, and a camera. And while that setup worked pretty well, Rober thought he could do better. He recreated the effect with high-end equipment — namely, a Phantom camera. You can compare the results for yourself below — the first video shows the first setup, while the second shows the new setup with the high-tech camera.

The first time around, Rober used a tiny GoPro camera mounted on a cardboard disc that spun around using the motor of a ceiling fan. But the Phantom cam is too hefty (and pricey) to spin around like that, so Rober and another NASA engineer had to rig up something else — a scooter motor that spins two mirrors, which creates the effect of a constant rotation around the object being filmed, or in this case, shot. And the Phantom cam can stay safely in place, capturing images at 7,200 frames per second (the GoPro camera shot at 240 frames per second). The images captured by the setup really do mirror The Matrix’s bullet-time effects.

Rober and his friend redesigned the new setup more than a dozen times — I guess NASA employees know a thing or two about trial and error! They particularly struggled with the mirrors, as nearly a third of the light disappears when it passes through a conventional mirror, and the Phantom’s high shutter speed requires a lot of light. They ended up using acrylic, front-surface mirrors, which lose far less light, but because they’re slightly curved, there is some distortion of the final images.

They also struggled a bit with choosing a camera lens, having to balance light and distance. They ended up choosing a 50mm lens for the light, but with a wider point of view if makes the object being filmed seem small and far away. For the final video they had to crop and stretch it, which also degrades the final cut just a bit.

But hey, challenges aside, this is some entertaining eye candy. And I’m particularly glad to know there’s still science fun to be had after NASA!

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