I have a little release today that isn't a full tutorial, but it should get you started if you are interested in learning how to "paint with light".
If you want to get technical, photography by itself is "writing with light"; coined from two Greek words (photo and graph(y)) . The word "photo" transcribed from greek is defined as "light; ultraviolet and infrared radiation; radiant energy"* and word graph or graphy is given a definition of "to scratch; to write, to record, to draw, to describe; that which is written or described"*. Didn't you all wanted to know that?
I'm sure you all remember when you were kids...remember those sparklers you used to get and your parents would light? I wonder how many of you did the very same things as we did. We'd write our names in the darkness of the sky, or draw hearts and circles and you could always see the after effects of that for a few seconds before it faded into nothing.
That's just one way of painting with light. Though our eyes record it for mere seconds, our cameras can record it and spit it out in a printable format.
There are a number of different techniques for painting with light and you can do it using a studio setup or outdoors, with small handheld laser pointers and flashlights to outdoor floodlights.
The pdf file I've got here is one I developed as a handout for a studio workshop, and describes in general the techniques we would use in the studio. While there are some specific settings given, they were developed for this location and conditions that the workshop would be given in. You'll have to play with them a little, but there should be enough here to get you going. Painting with light, like photography, is about experimentation...and exploration...and fun.
The handout also includes links to and information about two of my very favourite light painters - one works on large, eerie landscapes with fantastic colours, the other literally draws a new scene over the landscape around. Please take time to visit them both. You'll learn a lot more from them, than I could ever teach you.
Download the workshop handout here: Painting with Light
PLEASE NOTE: THE PASSWORD TO UNLOCK THE PDF IS notheft
*Reference: definitions from WordInfo