I just got a chance to play with this tonight, I think it’s something fun to try during night photography. If you have uneven lighting from artificial sources or a subject that is coming out too dark during a long exposure photo, you can paint it with light. Literally you take a flashlight and paint the area you want to lighten with the light beam.
I used this on the trees in the middle and right on the photo above (the light streaks are from a passing car). I liked being able to control the light, but the light on the trees in the foreground was a different temperature than the trees in the background which were lit by a street light.
This was a fun experiment tonight except for the fact that the neighbors might think we were nuts for shining flashlights at the trees across the street and our friendly local bear was in the trees as well… eeek, scary!
No light painting here, but this is my favorite shot from the night. 5 minute exposure with no moon, just streetlights at f5.6, ISO 400.