A few days ago, a seemingly bizarre video of a “magic” helicopter made the rounds of the internet. It showed a helicopter taking off from a helipad with no effort and no movement from its rotor blades.

But unfortunately, it’s not a new invention of the helicopter that needs no rotors. It’s a camera trick. The video-maker perfectly synced his camera’s shutter speed to the speed of rotation of the blades to create the optical illusion.

Helicopters frequently look strange or odd on camera, just like all fans do. The video below by How Stuff Works explains why.

“Shutter speed addresses the amount of time the camera spends gathering light every time it takes a picture. And faster shutter speeds can create strange patterns, or even make the individual blades become visible. When combined with a frame that’s synchronised almost perfectly with the rotation of spinning blades, they can appear to be stagnant.”