Originally Posted by Mulder
The dispersion properties of the light from HID bulbs is different from halogen bulbs, because the light is generated by different means. In addition the amount of light emitted by the HID bulb is much greater. Therefore the optical design of the housing must be different to properly accomodate the type of bulb being used.
I understand why they are different. But what is different about them? How are they made, compared to that of a halogen housing. Basically the point of my question is to see if the housing could be modified to give optimum output for an HID retrofit.