Originally Posted by goXtreme
OK, now I am lost, please explain, just a little bit...
High Intensity Discharge or HID bulbs are much brighter than halogen bulbs, but are designed to be used in a projector style housing. Our trucks come from the factory with a halogen bulb and a halogen style reflector in the headlight housing. There a ton of HID retrofit kits all over the place, but they don't work to their full potential because they are just poped into the stock halogen reflector. If you have ever seen a riced out honda civic with bright white or blueish tint lights that blind oncoming traffic, that is a HID retrofit kit in a stock reflector. Factory halogen housings are designed to deliver a certain light pattern, This pattern is dependent on the position of the bulb's arc from the reflector. HID bulbs are not the same as halogen so the light reflected in the housing is scattered and inconsistent. Retrofitting a projector into the headlight housing fixes this. Projector housings are how OEM HID housings are designed.
OEM Lincoln HID projector: