Creating a Lake or Swamp Effect Using Fog

One of the most common, easiest to implement, and most overdone special effects in the theater is the use of fog. Fog can be introduced onto the stage by any number of fog machines available for purchase or rental, and delivery systems. A variety of machines in a variety of sizes are available to create the correct volume of smoky stage fog in a production. One especially attractive effect that can be achieved with a fog machine and a few other components is the appearance of a lake or a swamp on stage.

By manipulating the fog such that it stays low on the stage, creating a continuous sheet at most one foot high off of the stage, we can create the appearance of a body of water. Introducing additional scenery, such as trees and rocks poking out through this “sea” of fog, or perhaps a boat traveling across the stage, can create a very realistic effect. The key technical aspect of this effect is assuring that the fog remains low on the stage. The way to do this is to decrease the temperature of the fog as it leaves the fog machine and regulate the amount of fog that gets released, such that it doesn’t begin to scatter and fill the stage and house. While cooling units can be purchased or rented for this purpose, a unit can easily be constructed out of materials as simple as some duct tape, a properly sized cardboard box, and some dry ice.

By cutting holes in two opposite sides of a cardboard box, filling it with dry ice, and placing the output of a fog machine in one of these holes in the box, cool, low-lying fog will stream out of the other end of the box. Duct tape should be used to make the box as tight as possible to prevent heat transfer and fog leakage. The volume of fog released should be turned down such that it can be cooled enough while in the box to sit low on the stage when it is released. The best way to determine this proper setting is to experiment. Quick dissipating fog should be used as well, to make sure the fog rolls off the end of the stage, and is dissipated before it warms up and drifts too far into the house.