"I wish you had interacted with the last at <a href=""https://www.youtube.com/watch?v=tozuzV5YZ7U&amp;t=2m31s"">2:31</a> where it's stationary in specific points. What would happen if you place your hand where there is no visible laser?",(reply>), @Nick Stotter so the hand doesn't light up but it kills the rest of the laser (that would be behind the hand),(reply>), Nothing. It’s blinking but always there. It’s only the shutter that makes it look like it’s in specific points