Actually, I have done some back when I used film. But that was exclusively with long exposures, and just waving lights around to create "line art" in the photograph. I find most "line art" boring, though. A long exposure is a continuous unbroken form of just image averaging over time. One could take many exposures and combine them. Digital on a tripod will have virtually prefect alignment, and lets you pick and choose how that's done. One idea I've had, and have yet to do, is to take a picture of many lightning flashes in a storm, with a different color filter for each. With digital, all I need to do is just take a lot of pictures, pick the ones with lightning flashes I want, and colorize them as desired, changing the colors around in any shade until I get a better result. And I'm not limited to the few colors I can get lens filters for. So instead of one long exposure, I plan to do multiple exposures, and mix the best results. Now as to the mixing, the next question I'm considering is how to combine. The more obvious way is to just average the shots together, after any biasing like colorizing. But I'm thinking I might get better results in some cases by just choosing which source is brightest separately for each pixel. Any thoughts on that? Normally I would do light painting by taking a flash around, and snapping it from various angles, especially from behind obstacles, in other rooms, etc. But I'm also thinking of the idea to let lightning do that for me in night storm shots.