In this scene I was going to try two different effects. What I wanted here was the light source coming only from the camera position - like someone holding a flashlight. I used a default radial behind the camera. It looks good, but it's far too bright and doesn't convey a sense of eerieness that a flashlight would. The second effect I wanted to try was a complete bust. I wanted to put a light in the tubes, within the circuitry so that it would shine through in tiny dots but when I replicated the tubes, all the light washed out the scene.