At Los Angeles Opera when we need to provide smoke or fog effects we have a couple of options for available and safe technology. Most applications call for our liquid nitrogen (LN2) systems of which we have four machines. The machines are located in the basement or “trap room” beneath the stage. For this production of Albert Herring the staging requires a gas furnace “explosion”. In synchronization with an explosion sound effect we cue a two to three second blast of LN2 “smoke”.
 

Each LN2 machine is a large reservoir filled with purified water which is heated to near boiling. Operating the controls allows for precise integration of the LN2 gas into the reservoir. When this mixture takes place, the white cloud-like “smoke” is created. A series of valves and hoses are used to regulate and distribute the effect.
 
The resultant effect product is a non-toxic mixture not dissimilar to the clouds in the sky. This provides for a spectacular effect that does not bother the singers.
 

In addition to Albert Herring, the effect will be used extensively in our upcoming production of La Boheme.