Halogen/HID FACTS!!

[Sparky67]

Long term, the increased amount of UV light from the HID's will cause the plastic to break down extremely quickly in comparison with a good glass.

Rhino,

According to your post, you claim that HID's produce UV (Ultraviolet light). Sorry, but HID's produce light that is in the visible spectrum, not Ultraviolet light. Here is Photonic Spectrum Reference Chart.
http://www.imt.liu.se/edu/courses/TB...6.Spectrum.pdf
Xenon HID headlights produce some continuous spectrum white light, but much of their luminous power is generated as broadened spectral lines, including blue lines at 405, 435, and 475 nm.
http://www.pubmedcentral.nih.gov/art...?artid=1771460



Also, most plastic housings now use an optical coating to protect against UV light from the sun.

Jeff

http://www.kodakgallery.com/67rscamaro

[Rhino]

Sorry, but HID's produce light that is in the visible spectrum, not Ultraviolet light.

I've heard the arguement both ways. The HID arc itself produces a very high level of UV light. According to what I've read, the majority of this light is caught by a filter on the bulb itself, although the remaining UV, or near UV, light that escapes is much higher than with a halogen bulb.

Here is an excerpt from one of the links you provide:

Glare countermeasures include adaptive headlights and ultraviolet headlight systems. Adaptive headlight systems monitor and compensate both optically and mechanically for changing traffic, road, and meteorological conditions. Ultraviolet headlight systems project invisible ultraviolet radiation, improving the visibility of fluorescent highway markers, signs, and objects without increasing glare for oncoming drivers. Ultraviolet radiation is especially valuable in fog because highway signs can fluoresce in the visible spectrum when exposed to ultraviolet radiation, but backscattered ultraviolet radiation is invisible so it can’t reduce the contrast and legibility of the signs. This situation is similar to retinal imaging in patients with asteroid hyalosis. Ordinary reflectance images have poor detail because back scattered flashlamp light reduces the contrast and visibility of retinal features. In fluorescein angiography, however, back scattered blue light from the photographic flash is blocked from reaching the camera by a barrier filter, and green fundus fluorescence provides good retinal image contrast.

To me that sounds as if UV light is getting emitted. To me it doesn't seem as if it's 100% related to HID's, but it's the only time Ultraviolet is referenced on the page.
Please correct me if I'm wrong. I'm simply basing this off of what I've previously read as I haven't done any studies into it myself.