Check out this post I copied from the Alfa Romeo digest. <p>They are in the midst of a bulb discussion and this post contains a link to an informative web page from where this info originated. Very interesting. Bound to cause controversy? (on this BB, not hard)<p>-----------------------------------------------------------------------------------------------<br>In the midst of all the discussion on the white/blue type lighting, I would<br>like to draw your attention to this very informative site:<br>http://lighting.mbz.org/tech/info/blue_bulbs/<p>I don't want to be a wet blanket but seek only to "enlighten" (ok, ok,<br>sorry). The author<br>has some very strong arguments against these lights. Some "highlights"...<br>(sorry again)<p>Quote:<br>ARE BLUE HEADLAMP BULBS DANGEROUS?<br>Yes, they are. Here are the nuts and bolts of why blue bulbs are a bad idea:<br>The output spectrum of halogen headlamp bulbs includes *very* little light<br>in the blue frequency range. These blue bulbs have a filter coating on them<br>that allows only the blue frequencies through the filter. Because very<br>little light is produced by a halogen bulb in this range in the first place,<br>it is only this very small amount--a tiny fraction of the total amount of<br>light produced by a halogen bulb filament--that ever reaches the road. This<br>can be confirmed this with a good-quality non-chromosensitive light meter;<br>even a very apparently-bright blue bulb actually throws very little light.<br>(snip)<br>Blue is the shortest wavelength/highest frequency color of visible light,<br>and, as such, scatters the most readily. This is why the sky is blue rather<br>than any other color from the sun's white output spectrum.<br>And, you may find it interesting to find a dark blue storefront sign or<br>something else that's a dark, pure blue against a dark background in the<br>absence of white light. From any appreciable distance, it's almost<br>impossible for your eyes to see the blue lighted object as a sharply defined<br>form...the edges blur significantly.)<br>(End quote)<p>Check out the web pages as there's lots more lighting info.<p>-------------------------------------------------------------------------------<p>Hmmmmm........ Sounds like I'll be waiting (and saving up) for that arc discharge unit if it ever gets here.<p>Enzo<p>The "A" List:<br>Wife's -- 98 A4 1.8T<br>Mine -- 84 Alfa Romeo GTV-6 that just got back from the body shop today, but now has a sticking and leaking RR brake caliper (heavy sigh)<br>Dog's -- 90 Acura Intega

I totally agree with the article.. I ordered a set for my headlights and after trying them out, I took them right back out.. Its like driving without any headlights on, the fogs were brighter than the headlights.. <p>Dmak 1.8TQMS Waiting for Xenon headlights also!<p>

... I'll keep everyone updated, I'll be working with a shop this winter on getting something like this put together. Expect pictures around Easter.<p>Cameron<br>

It's good to see that some things are still well researched on the internet these days, as many aren't. The comment on blue as a high frequency/low wavelength photon is correct. It would scatter the easiest because shorter wavelength photons have a higher probability of hitting an object (i.e. FM waves v. AM waves). Also, it would make no sense to put on blue bulbs anyways, as it would skew the light output towards the end of the light spectrum (red on one side, blue on the other). <p>Another issue, for me at least, is the quality of these aftermarket blue bulbs. Many of them don't look so great. I mean, call me paranoid, but I wouldn't want to be driving on I-5 late at night, going 85-90mph, and then all of a sudden have my lights go out. <p>But hey, don't they look so cool!!!! (sarcasm)<p>Edmund Louie<br>98 A4Q 30V

Hey Enzo,<p>The article is right. I put blue tinted bulbs in my Volvo's fogs over a year ago. I even went up in wattage from 55w to 75w bulbs. They are brighter if you look at them head on. However, from the driver seat, where it really matters, the performance is greatly diminished. The blue light does not give you ANY depth perception. I had rigged an extra switch in the car so I can turn on the fogs without the headlights, the lighting ability (or inability) of these bulbs is quite obvious.<p><br><i>The above Glorified "Me Too" post was brought to you by</i><p>James Wu<br>A4 Club of Vancouver<br>1998 Black/Onyx 1.8tqa<p><br><ul><li><a href="http://avant.extreme.com/va4">A4 Club of Vancouver</a></li></ul>

I'm waiting for the S4 unit, but have also done some research on Custom kit for the A4.. With the stock headlight unit at the moment upgrading to a xenon bulb is very simple, since the measurments for the xenon D2S bulb and the H-7 are very close.. So the beam patern should be correct..<br>I'm thinking of upgrading to a E code headlight unit then install a xenon kit.. What do you think?<p>DMak 1.8TQMS

In the October or November issue European Car test an A4 modified by AXIS (www.axiswheel.com). Somewhere in the text (think it is on the second page of the story) there is a sentence indicating that a company called Bellof has a Xenon kit for the Audi A4. Heard about it? Anyone?<p><br>Tommy A, 1.8T Avant Avantagarde

I called them and they were asking $1800 for the kit, which I think is rediculous! When the S4 unit comes, will probably be less.. <p>The company Bellof is a Japanese based company which makes the xenon capsules in different configuration as the halogen bulbs, this way the beam patterm does not have to be corrected..<p>You can take a look at their website @<br>http://www.jin.or.jp/g5/hid.htm<p>Dmak 1.8TQMS