Painting with light is a fun technique that gives great results. It is called painting with light because this is what you are actually doing while taking the shot – painting with light.
You don’t need much to experiment with this kind of shot, just make sure you have the following items:
1. A camera capable of long exposures – film cameras will work OK, but if you really want to get the most out of the shooting session, use a digital camera. You will be able to see the results in “real time” and make corrections as you go.
2. A nice tripod. Since you will be doing some long exposures you want to make sure your camera sits still.
3. A flash light – and by flash light I do not mean flash as in a speedlight, but the flash light or what our British will call a torch.
4. A dark location. This one is tricky. If you are going to shot at home – a dark room will be OK. If you are going to shoot outside – make sure that you are not doing this under a street light, or where a car can come by and “paint its headlight” all over your shot.
Here is how it’s done:
Set your camera on the tripod and take a sample shot with flash / lights on. This will help you verify that your composition is OK.
Set the exposure to a relatively long value. Stop down the aperture as much as you need. If you are outside do nothing. If you are inside – this is the time to turn off the lights.
Make the click. Once the shutter is open use your flashlight to light the stuff that you want to “paint”. You can use the flashlight as a brash, and “smear” the light, just like you would have done with brush and paper. Or, you can use the light as a pen, and do precise work. Areas where you go slowly will be more lit then others. Be careful not to linger to much over the same stop – you will burn it. (The machos amongst you will correctly identify this as the “I forgot the iron on the shirt” phenomena).
Once the shutter closes, you are a free person again. Inspect your image and make corrections. via
Do It And How 