zam2000

Good reading

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<i>There are many companies and private merchants out there that will advertise 7000K, 8000K, and even 12000K HID kits. Most of these vendors lurk around on e-bay, online car forums, websites, and ricer accessory shops. 100% of the people that buy these kits do so because they are uninformed, uneducated, or misguided in the field of lighting, and will buy these junk kits thinking two things: that these bulbs are brighter and/or that they will perform better. These are both untrue. Perhaps this misconception and frenzy for purple lights originates from BMW and Audi's infamous projector HIDs.

So here's the *real* low down... Philips is the number one manufacturer of HID bulbs. The Philips OEM D2S bulb is rated at 4100K at 12.8 volts and produces 3200 lumens of light. The Philips Ultinon D2S is 5800K at 12.8 volts and produces 2400 lumens of light. As you can see, with all other factors remaining constant, the brightness of an HID bulb declines the higher up the color index you go. Vision, a Korean bulb manufacturer, makes an 8000K bulb, which they used to advertise on Acura-Forums as 2000 lumens bright. This is barely a marked improvement over halogens, and will produce more glare and eye fatigue than it is beneficial. 4100K has been proven through tireless independant research by the Germans and Japanese to be the most functional, truest white and thus the brightest possible color temperature (ceteris paribus).

Every car manufacturer in the world (including BMW and Audi) uses none other than a standard 4100K gas-discharge bulb. The reason being is that 4100K is daylight white in color and produces the same color visible light as direct sunlight. This is least fatiguing functional color on the eyes and produces the most comfortable contrast on the road. </i>

<b>So the big question now is: Why do BMW and Audi lights appear blue when they use a white bulb? </b>

<i>
Well, this coloration is the result of the light projectors; the lenses: it's transparency, it's curvature, the tiny grooves etched into it; the projector assembly, the shield, and the reflector bowl. All these components work together to produce a signature of light unique to that particular optic's design. On the Audi and BMW projectors, the lens curvature at the edge bends the white light producing a "prism effect". White light is broken down to it's fundemental colors. Since blue lights is high energy it is absorbed last and thus travels farther. So with this prism effect, you'll notice that BMW HIDs are only purple and blue from the sides, the top, and the bottom, but are always daylight white on the road and in the beam pattern. This phenomenon can be demonstrated when you watch an oncoming BMW hit a pothole or speedbump in the road and the car's nose pitches up and down. The headlights will flicker and "throw colors off", but returns to a solid-white beam pattern directly on the road.

Trying to emulate this color-flickering effect with a solid-state blue or purple bulb is only detrimental to lighting performance, but more importantly endangers motorists around you......... </i>

Alexbenz

philips is a great brand but i've seen there share of problems with ballasts and also to get replacements is a nightmare with them........

raymond g-

Found another great HID bulb FAQ read that I wanted to highlight for folks here. Have all my parts assembled and ready to cut into my Taiwan clear lens and shoehorn Hella proj bulb/HID/ballast. But still scouring the Web for all those rice cars et al who've done this looking for tips. I'm not in any rush so happy to learn from other people's mistakes. I was intrigued in reading of mention of switchable ballasts. Anyhoo, here is the good read.....

D2R v D2S etc

BT320

That makes for a very good read Ray, thanks for the info.

Fast55

I've got to disagree on the 4100K being the "best" or brightest color temp. My 430 sport had a conversion from "Serious Vision" that was supposedly 5000K. It is definitely brighter than the OEM 4100K HID's in my 55. I don't think all of the difference was bulb hours either. Anyone know where to get the 5000K D2S bulbs for our OEM Xenons at a reasonable price?

zam2000

Ive even seen post claim that 8000K give out the brightest light !!!.

After all, it's all subjective, as long as you're happy w/ your light, that all matter.

Lab test & result doesn't mean anything. Philips and Osram know nothing about light !!!

raymond g-

Fast 55:
I'm thinking that though the eyeball views the 5kº light to be brighter, the measured brightness (eg in candela) indicates otherwise.

Fast55

That's possible, but as you say, what looks the brightest is what I'm looking for. I did find some 6000K replacement HID's at HID Express, but so far, the 5000K looks the best of what I've seen, just haven't found it in a D2S OEM style of bulb. 8000K was pretty, but worthless for seeing down the road. I can imagine what 10K would look like. Anyone know where to get the Phillips 8122+ 5000K bulbs?