If you think about it, all photography is painting with light. Even the word photography in Latin literally means painting with light. Every time you make an exposure the light is writing or painting on the digital sensor to record the photograph.
It was almost totally dark except for a sliver of orange light along horizon when I took this photo. This is a single 15 second exposure during which time I used a flashlight to paint light onto the tree and the reflection in the water. It was shot with a 16 by 35mm Canon lens set to 16mm. The ISO was 200 in my Canon 5D Mark II camera.
In this case painting with light means using a flashlight to actually paint light on to the subject during the exposure. This is how I created the photograph, Cyprus Sunset. Without using a flashlight to paint the cypress tree, there would have been no contrast between the dark tree and the dark night sky. Using the flashlight to brighten the tree while the shutter was open created the contrast I needed in this photograph.