There are incredible feats of engineering going completely unnoticed all around us. The way a high speed camera shutter works is one of them.
Luckily, the Phantom slow-mo cam—everyone's best friend—exists to show us just how awesome camera guts are at 1920 frames per second. We've seen similar on a Canon 60D, but what we have here is a Nikon D4 shooting photos at a rate of 10 frames per second. For each photo, the mirror flips up and the first curtain drops, exposing the image sensor for 1/200th of a second. Then, the second shutter drops to complete the exposure. Bravo.