Field Angle Math

Posted by on December 3, 2012 in Theatre, Tools and Methods | 0 comments

Field angle math: A lighting designer’s vital tool.  It’s how one decides what fixture is the right instrument for the job, and where to put it.   Sometimes I sketch out a drawing for just a single fixture, perhaps to illustrate the idea for the actors and directors who won’t have the real light to work with until tech rehearsal:


Simple elevation sketch showing the shaft of light through a window

Copyright Julie Seitel



..And sometimes I sketch out every system in the show on a single drawing:


Field angle math for Omnium Gatherum

Field angle math for lighting systems in Omnium Gatherum. Copyright Julie Seitel.


I prefer this method to the old yellow-trace-paper-overlays.  Yes, I know, I just dated myself bigtime. And yes, I do sometimes do it with VectorWorks… but I get a lot out of the mental process that goes with physically drawing the whole line, versus just clicking endpoint locations.  It makes me really think about the beam edges and shuttercuts.