Charlie bar

plural Charlie bars

1. broadcastingA vertical bar positioned in groups to break up the illumination from a light source.

   […] traditionally these include things such as vertical Charlie bars — vertical wooden bars used to create shadows.

   2013, Blain Brown, Cinematography: Theory and Practice, page 115

   2 more examples

   Adding texture to lights. Charlie bars (vertical bars, in this case made from tape on an open frame) and also some lace create texture in the scene.

   2012, Blain Brown, Motion Picture and Video Lighting, page 56

   Charlie bar A 1- to 6-inch wide by 3-foot long strip of wood with an attached pin used to create shadows on an object (thin long flags, gobos).

   2013, Michael Uva, Sabrina Uva, Uva's Rigging Guide for Studio and Location, page 260