In the Shanghai's metro, I was really impressed by the ads using persistence of vision in the tunnels :) https://www.youtube.com/watch?v=WsdF834vXkQ&t=0m32s htt

In the Shanghai's metro, I was really impressed by the ads using persistence of vision in the tunnels :) https://www.youtube.com/watch?v=WsdF834vXkQ&t=0m32s https://www.youtube.com/watch?v=WsdF834vXkQ&t=0m32s The quality is better in person than in this video, because the camera's shutter speed creates artifacts.