Equipment Detail

Source Four  (1992 - present)
Electronic Theatre Controls / ETC

Source Four

Official website:

Fixed Focal Length
Available in 575W or 750W variations:

Source Four 5 degree (360mm colour frame)
Source Four 10 degree (290mm colour frame)
Source Four 14/70/90 degree (190mm frame)
Source Four 19/26/36/50 degree (160mm frame)

Source Four Junior Zoom 25 - 50 degree (160mm frame) 575W only
Source Four Zoom 15 - 30 degree (190mm frame)
Source Four Zoom 25 - 50 degree (190mm frame)

The Source Four (named after the four filaments of the HPL lamp) was invented, along with the HPL lamp, by Dave Cunningham and Greg Esakoff of Entertec in Los Angeles. ETC pays them a royalty from each fixture sold. 

Related Shows

Related People:


Patent - David Cunningham (July 1991)
[External Website]

25 Years of the ETC Source Four (August 2017)
[External Website]

Source Four at 25 (October 2017)
[External Website]
From Lighting & Sound International

Exhibits in the Backstage Heritage Collection

Back to Lanterns (Named) (Electronic Theatre Controls / ETC)