Artificial light has many uses such as the illumination of streets and hazardous areas, security lighting and increasing the hours of usage for outdoor recreation facilities but it can cause problems, light in the wrong place can be intrusive.

The home security lighting found in many domestic locations uses floodlighting controlled by a movement sensor using Passive Infra-Red (PIR).

Using PIR controlled 250 or 500 watt tungsten halogen floodlights may not be the best choice for lighting your house or garden because these lights: