Long Exposure Photography

In this technique, a scene is kept very dark and the photographer or an assistant takes a light source—it can be small penlight—and moves it about in patterns. The light source can be turned off between strokes. Often, stationary objects in the scene are illuminated by briefly turning on studio lights, by one or more flashes from a strobe light, or by increasing the aperture.
Water and long exposure
Long exposures can blur moving water so it has mist-like qualities while keeping stationary objects like land and structures sharp.