Light Graffiti, London, United Kingdom

Making a light painting doesn't necessarily need to be done in a dark room or at night. Sometimes using artificial light, like LEDs and mobile phones, or through the limited sunlight beaming in a curtained room creates a shadowing effect.
Live light painting
Light painting can be done interactively using a webcam. The painted image can already be seen while drawing, e.g. using the monitor or a video projector. Additional digital processing can be applied directly in the computer. This can be used e.g. to enable light painting during the day. A free software for that is myLightPainting.