Some years earlier, there was considerable dispute pertaining to retrofit HID packages for cars and trucks. This was as a result of the intolerable glare thrown off by improperly created HID retrofit systems. An understanding of the physics behind illumination optics reveals that halogens and also Xenon bulbs generate lighting designer in different ways, therefore impacting how a particular reflector housing and also lens is developed. Basically, H4 headlamps execute optimally with halogen light bulbs as well as HID light bulbs perform finest with reflectors as well as lenses made for them. For an HID individual, the 300 percent increase in light output can just be a good idea, specially in rural or backwoods where the only light when traveling is the one that the car's lights are throwing away.
However, having concealed lights even on low beam is equivalent or even greater than having halogen lights on high, which is why glare is a very real concern for oncoming vehicles. As mentioned, halogen and HID systems are fundamentally different because while halogens produce light through a filament, HID systems produce light through a gas arc.
In practical terms, what this means is that a reflector which has been designed to catch and reflect light given off by a halogen bulb will reflect light in the wrong places when used with a Xenon, or HID, bulb. If you as a car owner feels the need for an HID system, at the very least aim the lights lower than normal so that your much brighter Architectural lighting do not hit an oncoming vehicle's driver in the eyes.
In fact, it has been deemed that the only correct way to retrofit an HID system is to use a whole assembly which has been designed for an HID bulb from the outset. Reacting to the early complaints of too much glare for oncoming drivers, the big automotive lighting manufacturers have already come out with projector HID systems that can be retrofitted to older cars. For older cars with halogen systems, DIY types have managed to modify their vehicles' reflectors to better accommodate the beam patterns of Xenon bulbs.
Usually, this involves baking the lighting assembly to remove the lens, cutting/reshaping the reflector and then resealing the lens and reflector assembly with silicone. Fortunately for the buying public, HID systems have become commonplace in newer cars and modifying your system can be as simple as replacing your OEM Xenon bulb with one having a higher wattage.