During the class 'Seeing light - Emotional effects of light when composing images' while studying Media Technology, two colleagues and I got the chance to climb a vacant attic and play around with flashlights and LED lamps. We 'painted' with light using not the common technique of long-exposing the scenes frame-by-frame, but by generating the effect afterwards, in post.
Equipment used: Canon 550D.
Software used: After Effects, Premiere.