This light painting video created by 26-year-old Finnish director Anssi Määttä will give you something to rack your brain over. It is 100% live action without using any still photo, stop motion, or 3D stroke effect. The only plausible explanation we have found so far is a webcam program called Light Paint Live that allows you to paint with light. But regardless of his method, Määttä's mystery video had us at the first stroke of light. Watch the video and see for yourself.
source: Anssi Määttä