HID light bulbs offer high light output. Metal halide, high-pressure sodium and xenon light bulbs are all types of HID bulbs. They all require ballasts to operate safely and properly. Ballasts serve several functions including providing starting voltages for HIDs. Ballasts are also used to maintain proper electrical flow to an HID bulb during periods of operation. Unlike incandescent and halogen bulb technology, HIDs do not employ delicate tungsten filaments in their construction, which makes them much more shock resistant.
Xenon HID bulbs are designed with a xenon-filled gas. The xenon gas allows the bulb to produce a very white light. The cool tones that xenon-filled HIDs produce offer improved visibility at night and in poor weather conditions such as rain, fog and snow. Improved visibility can lead to less driver fatigue. Low-beam xenon bulbs provide bright and wide road illumination while high-beam xenon bulbs provide a long visibility range.
The color xenon lights give off is much lighter than the color other types of lights, such as halogen lights, produce. Light that xenon HIDs produce is similar to daylight during the middle of the afternoon. Color temperature refers to a method of describing colors using a numbered scale. Color temperature units are expressed in kelvins. Colors with color temperature values closer to 1,000 produce yellow or orange light, similar to the light that a candle or an incandescent bulb produces. Colors with color temperatures between 5,000 and just more than 10,000 appear white to light blue.
Xenon headlights offer many advantages over traditional halogen headlights. Xenon headlight systems offer the driver reduced eyestrain and improved contrast. These headlights pick up reflectors from vehicles and road signs at much greater distances than other types of headlights. The average xenon light bulb produces over twice as much light output as certain halogen bulbs, such as the H7 halogen bulb. These bulbs also only require about two-thirds of the energy to operate compared to traditional halogen bulbs.