HID or more widely known as xenon lamps due to a gas inside the bulbs, have been growing immensely popular over the past few years, coming as standard or optional equipment on various European and Japanese marques.
Why is this lighting system taking over the automobile industry by storm? Apart from being brighter: at least 70% more light output than conventional halogen headlamps, it consumes only 35 watts per capsule, VS halogen’s 55 watts per bulb. In addition, it has a life expectancy of 5 times longer than standard halogen lamps (2,000 hours VS 500 hours or less).
It is very easy for a driver to distinguish a car equipped with HID or normal halogen headlamps, as HID’s lamp emits light with a slight bluish tint. HID headlamps have a longer and wider range, thus improving the driver’s fields of vision. Driver fatigue is also reduced as a road that is illuminated more brightly and widely by HID headlamps, reduces the amount of concentration needed, so drivers do not risk being weary so quickly.
A full HID system consists of:
Bulb
Ballast
Ignitor (external, integrated into ballast or integrated into bulbs)
Reflector/Projector
Lens
HID headlamps are rather sophisticated equipment. While many vendors and shops boast the facility and HID kits that can be installed to a car which does not have HID as standard, there is more to HID than just fitting a HID bulb in place of the halogen bulb. As the beam of light from a HID lamp is brighter, wider and further, the reflector or projector of the car must be aimed and aligned to ensure that it does not cause glare or affect the field of vision of other drivers on the road. The arc light source of HID headlamps is fundamentally different from that of halogen headlamps, thus HID specified optics are required to collect and distribute the light. To illustrate this point, think of it as putting on someone else’s glasses: you can probably make them fit your face, but you won’t see properly.