Cameras with an Auto Iris (AI) feature have the ability to compensate for large variations in light levels. Particularly useful for cameras that need to compensate for changes from bright sunlight to dark shadows. The auto iris circuitry is normally linked to a motorized iris drive that physically opens and shuts the iris on the lens. Closing a physical iris is a much better way to protect a camera from being damaged by bright sunlight then simply using electronics to reduce the signal strength.