Okay, maybe that title was a little click-baity, but these videos are still cool. This illusion occurs when the shutter speed and frame rate of a camera matches the speed of the helicopter’s rotor.
Check it out:
It’s pretty fun to pretend that these helicopters are just levitating into the sky without the rotor rotating. Turning the volume off adds to the illusion. 😆
Here’s an explanation oh how this illusion occurs. Pretty neat.