08-23-2016, 10:46 AM
Last edit by: IB Advertising
See related guides and technical advice from our community experts:
- Audi A4 B8 How to Replace Fog Lights<br>Step by step instructions for do-it-yourself repairs.
fog lights and HID
05-24-2009, 02:59 PM
#4
I think anyone should customize their car anyway they like. If you want LEDs behind that rings on the grill that flash to the beat of the music, you should have it. If you want skinny tires on over sized rims and slam the chassis to the floor, why not? It's all cool.
There are consequences to changing a lighting system from one illumination source to another. You should know that no one has crafted a conversion kit from halogen lamps to high intensity discharge lamps that works. Never mind that they cannot meet the legal specifications of FMVSS 108 (and similar European law.) For HID lamps a color temperature of 4300K is the optimum for human eye response. Higher color temperatures are available, but you see less because eyes are not as responsive to blue light. 6000K is about the practical upper limit for commercial lamps. Those that advertise more than that, are blowing smoke in your eyes. They make the lamps look blue or purple with dye on the lamp capsule. A real HID lamp should last about 2000 hours. The lamps sold in these kits are counterfeit, and 100 to 200 hours is tops, with significant light decrease after as little as 10 hours. HID lamps need about 25,000 volts to start, and about 80 volts to continue operating. This is done with a power supply, sometimes called a ballast or igniter. The ones in the kit are poorly made, using questionable materials. They usually burn out in about a year. The last thing is the reflector. The guys who sell these kit could not tell you what a correct beam pattern is, and if the pattern is wrong, how to correct it. The reflector design for a filament lamp is quite different from a reflector for an arc lamp.
Why not save your money and put it toward something useful like genuine HRE's or coat of NXT?
There are consequences to changing a lighting system from one illumination source to another. You should know that no one has crafted a conversion kit from halogen lamps to high intensity discharge lamps that works. Never mind that they cannot meet the legal specifications of FMVSS 108 (and similar European law.) For HID lamps a color temperature of 4300K is the optimum for human eye response. Higher color temperatures are available, but you see less because eyes are not as responsive to blue light. 6000K is about the practical upper limit for commercial lamps. Those that advertise more than that, are blowing smoke in your eyes. They make the lamps look blue or purple with dye on the lamp capsule. A real HID lamp should last about 2000 hours. The lamps sold in these kits are counterfeit, and 100 to 200 hours is tops, with significant light decrease after as little as 10 hours. HID lamps need about 25,000 volts to start, and about 80 volts to continue operating. This is done with a power supply, sometimes called a ballast or igniter. The ones in the kit are poorly made, using questionable materials. They usually burn out in about a year. The last thing is the reflector. The guys who sell these kit could not tell you what a correct beam pattern is, and if the pattern is wrong, how to correct it. The reflector design for a filament lamp is quite different from a reflector for an arc lamp.
Why not save your money and put it toward something useful like genuine HRE's or coat of NXT?
05-25-2009, 05:47 AM
#5
AudiWorld Member
Join Date: Jul 2008
Posts: 276
Likes: 0
Received 0 Likes
on
0 Posts
>>> PART 1 - RANT!
4100k is the optimal light.
Luxury brands hover around 4100~4300k
The blue "tint" is the projector that is cutting the light beam.
If you put in 6000k bulbs, you'll actually see less.
I'm young, i have NEVER had "blue" lights. Every time I see those "blue HID kits" I laugh at the simple fact that these people on dark country roads (where I drive) don't see half of what I can see and it's outright dangerous. Keep those in the showroom. ***Side note*** If you wanna get REALLY funky go to 12000k, they are purple! :P
>>> PART 2 - LIGHTS!
I actually was wondering if anything pencil beams wise was made for the fog light housing. (I drive long dark roads like 75% of the time, pencil beams == win for me!)
The power to the lights I don't think is an issue... you'll probably have to rewire from the actuator to the actual light (where the current that powers the light goes) Everything from the stock to the actuator is probably 12v or less.
CONS:
-Flicking HIDs on and off destroys bulbs... 100$ bulbs. Need to find a way to dim the light or deflect it (like bi-reflectors)
-Space constraints
What I found was motor cycle pencil beams (HID) They have a housing that contain everything. They are small enough to fit fog light holes. My only concern is the dimming of the lights for oncoming traffic! :\
If anyone can add to this... it would be much appreciated.
4100k is the optimal light.
Luxury brands hover around 4100~4300k
The blue "tint" is the projector that is cutting the light beam.
If you put in 6000k bulbs, you'll actually see less.
I'm young, i have NEVER had "blue" lights. Every time I see those "blue HID kits" I laugh at the simple fact that these people on dark country roads (where I drive) don't see half of what I can see and it's outright dangerous. Keep those in the showroom. ***Side note*** If you wanna get REALLY funky go to 12000k, they are purple! :P
>>> PART 2 - LIGHTS!
I actually was wondering if anything pencil beams wise was made for the fog light housing. (I drive long dark roads like 75% of the time, pencil beams == win for me!)
The power to the lights I don't think is an issue... you'll probably have to rewire from the actuator to the actual light (where the current that powers the light goes) Everything from the stock to the actuator is probably 12v or less.
CONS:
-Flicking HIDs on and off destroys bulbs... 100$ bulbs. Need to find a way to dim the light or deflect it (like bi-reflectors)
-Space constraints
What I found was motor cycle pencil beams (HID) They have a housing that contain everything. They are small enough to fit fog light holes. My only concern is the dimming of the lights for oncoming traffic! :\
If anyone can add to this... it would be much appreciated.
05-25-2009, 07:04 PM
#6
Audiworld Junior Member
Thread Starter
Join Date: May 2009
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
lol i love how you guys assume im trying to get a purple or blue color, or get phat rims, or get my LEDS to dance with my music, whats next should i go to pep boys and put some APC mods on?
i was just aiming for the 3000k color, yellow bulbs just look like regular halogens, and ive never had experience with any aftermarket HID kit.
yeah i did say it was really for cosmetic purposes, but i just prefer that color on my past cars, and on my motorcycle, from experience yellow fogs seem to pierce through the fog better, it doesnt really extend my field of vision but helps me be more visible to oncoming traffic, especially on the bike.
the only way ive achieved this is in the past was with a silverstar type bulb, inside a yellow capsule fog lamp, or putting a yellow tint film.
i dont need genuine wheels, and im sure all of us already have some coat of (name your brand) for protection.
i like how you were informative about HID and lighting and aftermarket kits, but you could've left your assumptions out.
i was just aiming for the 3000k color, yellow bulbs just look like regular halogens, and ive never had experience with any aftermarket HID kit.
yeah i did say it was really for cosmetic purposes, but i just prefer that color on my past cars, and on my motorcycle, from experience yellow fogs seem to pierce through the fog better, it doesnt really extend my field of vision but helps me be more visible to oncoming traffic, especially on the bike.
the only way ive achieved this is in the past was with a silverstar type bulb, inside a yellow capsule fog lamp, or putting a yellow tint film.
i dont need genuine wheels, and im sure all of us already have some coat of (name your brand) for protection.
i like how you were informative about HID and lighting and aftermarket kits, but you could've left your assumptions out.
Trending Topics
05-26-2009, 05:03 AM
#8
AudiWorld Member
Join Date: Jul 2008
Posts: 276
Likes: 0
Received 0 Likes
on
0 Posts
yeah i did say it was really for cosmetic purposes, but i just prefer that color on my past cars, and on my motorcycle, from experience yellow fogs seem to pierce through the fog better, it doesnt really extend my field of vision but helps me be more visible to oncoming traffic, especially on the bike.
Actually I would be all for 3000k range for a bulb if you simply want a REALLY kick *** HID fog light. ++ on that idea. I think the idea is that whiter light reflects on humidity better (hence you can't see) but yellow does not as much. I suspect yellow is the nice middle of visible usable light but that also cuts through fog!
Props on the idea, let us know how it turns out!
05-26-2009, 06:12 PM
#9
Please, I made no assumptions, rather said how I feel about mods made to cars. I make no judgment on how people customize their cars. I hate to see anyone make a choice about lighting without information to allow an informed decision.
There is no good reason why fog lights are yellow. The following was written by Dr. Craig Bohren. He is the author of Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics. It is a non-technical book and a pretty good read.
"First I'll give you the wrong explanation, which you can find here and
there. It goes something like this. As everyone knows, scattering (by
anything!) is always greater at the short wavelength end of the visible
spectrum than at the long wavelength end. Lord Rayleigh showed this, didn't
he? Thus to obtain the greatest penetration of light through fog, you
should use the longest wavelength possible. Red is obviously unsuitable
because it is used for stop lights. So you compromise and use yellow
instead.
This explanation is flawed for more than one reason. Fog droplets are, on
average, smaller than cloud droplets, but they still are huge compared with
the wavelengths of visible light. Thus scattering of such light by fog is
essentially wavelength independent. Unfortunately, many people learn
(without caveats) Rayleigh's scattering law and then assume that it applies
to everything. They did not learn that this law is limited to scatterers
small compared with the wavelength and at wavelengths far from strong
absorption.
The second flaw is that in order to get yellow light in the first place you
need a filter. Note that yellow fog lights were in use when the only
available headlights were incandescent lamps. If you place a filter over a
white headlight, you get less transmitted light, and there goes your
increased penetration down the drain.
There are two possible explanations for yellow fog lights. One is that the
first designers of such lights were mislead because they did not understand
the limitations of Rayleigh's scattering law and did not know the size
distribution of fog droplets. The other explanation is that someone deemed
it desirable to make fog lights yellow as a way of signaling to other
drivers that visibility is poor and thus caution is in order.
Designers of headlights have known for a long time that there is no magic
color that gives great penetration. I have an article from the Journal of
Scientific Instruments published in October 1938 (Vol. XV, pp. 317-322).
The article is by J. H. Nelson and is entitled "Optics of headlights". The
penultimate section in this paper is on "fog lamps". Nelson notes that
"there is almost complete agreement among designers of fog lamps, and this
agreement is in most cases extended to the colour of the light to be used.
Although there are still many lamps on the road using yellow light, it
seems to be becoming recognized that there is no filter, which, when placed
in front of a lamp, will improve the penetration power of that lamp."
This was written 61 years ago. Its author uses a few words ("seem",
"becoming recognized") indicating that perhaps at one time lamp designers
thought that yellow lights had greater penetrating power. And it may be
that because of this the first fog lamps were yellow. Once the practice of
making such lamps yellow began it just continued because of custom."
Craig Bohren - 1999
If you wanted to be seen better by on-coming traffic, a strobe would be much more visible, but with the exception of emergency vehicles, they have not been used very often on cars.
There is no good reason why fog lights are yellow. The following was written by Dr. Craig Bohren. He is the author of Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics. It is a non-technical book and a pretty good read.
"First I'll give you the wrong explanation, which you can find here and
there. It goes something like this. As everyone knows, scattering (by
anything!) is always greater at the short wavelength end of the visible
spectrum than at the long wavelength end. Lord Rayleigh showed this, didn't
he? Thus to obtain the greatest penetration of light through fog, you
should use the longest wavelength possible. Red is obviously unsuitable
because it is used for stop lights. So you compromise and use yellow
instead.
This explanation is flawed for more than one reason. Fog droplets are, on
average, smaller than cloud droplets, but they still are huge compared with
the wavelengths of visible light. Thus scattering of such light by fog is
essentially wavelength independent. Unfortunately, many people learn
(without caveats) Rayleigh's scattering law and then assume that it applies
to everything. They did not learn that this law is limited to scatterers
small compared with the wavelength and at wavelengths far from strong
absorption.
The second flaw is that in order to get yellow light in the first place you
need a filter. Note that yellow fog lights were in use when the only
available headlights were incandescent lamps. If you place a filter over a
white headlight, you get less transmitted light, and there goes your
increased penetration down the drain.
There are two possible explanations for yellow fog lights. One is that the
first designers of such lights were mislead because they did not understand
the limitations of Rayleigh's scattering law and did not know the size
distribution of fog droplets. The other explanation is that someone deemed
it desirable to make fog lights yellow as a way of signaling to other
drivers that visibility is poor and thus caution is in order.
Designers of headlights have known for a long time that there is no magic
color that gives great penetration. I have an article from the Journal of
Scientific Instruments published in October 1938 (Vol. XV, pp. 317-322).
The article is by J. H. Nelson and is entitled "Optics of headlights". The
penultimate section in this paper is on "fog lamps". Nelson notes that
"there is almost complete agreement among designers of fog lamps, and this
agreement is in most cases extended to the colour of the light to be used.
Although there are still many lamps on the road using yellow light, it
seems to be becoming recognized that there is no filter, which, when placed
in front of a lamp, will improve the penetration power of that lamp."
This was written 61 years ago. Its author uses a few words ("seem",
"becoming recognized") indicating that perhaps at one time lamp designers
thought that yellow lights had greater penetrating power. And it may be
that because of this the first fog lamps were yellow. Once the practice of
making such lamps yellow began it just continued because of custom."
Craig Bohren - 1999
If you wanted to be seen better by on-coming traffic, a strobe would be much more visible, but with the exception of emergency vehicles, they have not been used very often on cars.