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Electronic Theatre Controls Inc

Bench Focusing a Source Four ERS


Bench focusing a Source Four is a necessary part of your regular maintenance on Source Four fixtures. It properly aligns the lamp with the reflector to ensure you get a nice flat field that produces optimal lumen output, and prevents gels from burning through too quickly.

Basic Bench Focusing Steps

  1. Create a hard edge by adjusting the barrel
  2. Center the hot spot by rotating the outer knob clockwise until the knob is tight. Loosen the knob until the hot spot is centered in the field
  3. Flatten the field by rotating the inner knob. A hot spot or hole appears in the field if it is not aligned correctly.

You can also watch ETC's Bobblehead Fred Short on Bench Focusing a Source Four below, and use the following images to reference knob placement and field alignment.