What are these types of lights called?

Question

Generally before an arena sport game starts, they have four lights rotating around the arena floor projecting an image. They are all black, and mounted underneath the big jumbotron. the lights I am talking about are casting an image logo onto the ice surface in this video: http://youtube.com/watch?v=yQWZP-74HAQ

Answer 1

The lights are actually a few different components put together. Though particulars may vary, here are the basic components:

1. The light itself is typically an ellipsoidal light commonly found in theatre and concert shows. It projects an even, tight beam rather than washing an area with light.

2. Motion control - either these are controlled by a simple rotating motor or they are hooked to a computer system with custom paths programmed into it. This is an additional feature of the light fixture itself and a compatible light board.

3. Gobo - a gobo is a slide inserted into a light in a specific shape to be projected onto a surface.

You can find cheap, simplified effects similar to this at parties and weddings using PocketScan lights. They use mirrors to control the motion of reflected light by use of a joystick or something similar.

Laser effects are also used in these situations, but they look different than what you're describing.