To paint with light, the surrounding area must be dark. A longer exposure is needed to capture the streaks of light from the moving light source. Because the photo is mostly black the light source stands out no matter what position its in. The subtle thin strokes of the light makes the light painting it look elegant. To capture a person with light painting a strobe is needed. Once the strobe light it is flashed, the light source can enter the photo area and paint streaks of light around the subject.
