Auto Lighting thread : Post all queries about automobile lighting here

[TARUL]

What bulbs are you using on the headlamps?How do your fogs illuminate the road when it's raining?

[Thad E Ginathom]

All standard. I wouldn't use fog lamps in rain unless it was very heavy, but Chennai doesn't give me many days to find out the answer to this one, I'm afraid.

[Ram]

Originally Posted by s0uljah

Any bulb can be replaced on the car as long as you get the correct specification and wiring.

Check the specification of the stock fog lamp (h7, h8 etc) and then buy a 55 or 50watt crystal vision/blue vision.

You would be lost in the rain/fog though :(

@s0uljah, Why would @gauravchawla be lost in the rain/fog?

[Ram]

Originally Posted by TARUL

Hey gaurav I would strongly suggest not to go in for white fog lights as the intensity of light given out by these bulbs are very poor.The best alternatives for white lights are xenon's which are expensive but worth the price.

@TARUL, Why do you say that the intensity of white fog lights are very poor?

I agree that Xenon HIDs are brighter but @gauravchawla is not changing from Xenon HIDs to white fog lamps.

I understand he is intending to change from yellow fogs to white ones.
Am I mistaken?

[anupmathur]

Originally Posted by gauravchawla

Also, is it possible to repace indicator bulbs aswell ..to white!!

Do you mean turn indicators?
Why would you want to do that? Unless you mean to change the bulbs to white and the glasses/lenses to orange.
There are conventions on the colour turn indicators have to be.

[headers]

The yellow fog lamps have a better penetration power in real fog. The white ones on some cars are placed so low and their focus is also towards the edges of the road. Changing the fog lamps to any color but yellow may look good but fail the purpose for which it was designed.

Also, most later cars have fog lamps for show rather than purpose :(

[TARUL]

Originally Posted by headers

The yellow fog lamps have a better penetration power in real fog. The white ones on some cars are placed so low and their focus is also towards the edges of the road. Changing the fog lamps to any color but yellow may look good but fail the purpose for which it was designed.

Also, most later cars have fog lamps for show rather than purpose :(

finally some one supports me.I have tried most of the brands of white fog lamps from philips crystal vision to osram etc.These bulbs look good but cannot be matched to yellow bulbs in terms of visibility on the road.

[Ricky_63]

Fog Lamps are meant to serve a purpose OTHER than in the looks department. All the Blue & White lights in fogs will TOTALLY defeat the purpose of being there in the first place. Stick to OE yellowish gold colour or Yellow.

Visibility in REAL FOG will be close to ZERO with Blue or White lights.

I can say this from personal experiance - in 1999 on 31st DEC. I was returning from GK2 to Gurgaon in my Zen with Stock lights, I missed turns & ALMOST collided with road dividers, it was Foggy as hell.

The next morning I got Hella Yellow Fog Lamps installed on the car, believe me the difference was unbelieveable. It helped me avert many mishaps.

So guys SAFETY FIRST !!!!


Cheers

[s0uljah]

Originally Posted by ram

@s0uljah, Why would @gauravchawla be lost in the rain/fog?

Been discussed many times.

White light disperses easily. In rain and fog it just cannot illuminate.

The yellow on the other hand can penetrate through the water droplets/fog and improve visibility.

The best combination for visibility EVER :

Headlamps - 4300k (High/Low) HID
Fogs - 3000k HID

3000k = pure yellow.
4300k would have a hint of white, like Narvas I reckon.

[Ricky_63]

Originally Posted by s0uljah

Been discussed many times.

White light disperses easily. In rain and fog it just cannot illuminate.

The yellow on the other hand can penetrate through the water droplets/fog and improve visibility.

The best combination for visibility EVER :

Headlamps - 4300k (High/Low) HID
Fogs - 3000k HID

3000k = pure yellow.
4300k would have a hint of white, like Narvas I reckon.

PUURRRFECT explanation !!! That should satisfy most questions !!


Cheers

[binoyb22]

@Tarul

How much will the xenon's(head lights and fog) cost?? iam planning to change it for my Getz.

[rranjith_kum]

Originally Posted by s0uljah

3000k = pure yellow.
4300k would have a hint of white,

with that you can go for the yellow; make sure it meets the regulation.

[shuvd]

Does the law require you to have a projector setup in fogs if you intend to use HIDs as fog lamps?

@ Binoyb22 - IIRC, HIDs start from 6k INR.

[ram_hyundai]

See my humble request-you are not authorised to change the indicator lights.There are norms for such things buddie.If you change the bulbs to white then the glass have to be orange.Is it really required to do such a mod.
ram

[Ram]

The original idea to have yellow fog lamps was to benefit from color scatter.
This could happen if the water droplets were approx. the same size as the wavelength of colored light.

But visible light wavelengths vary from 400 to 700 nanometres, i.e. 0.4 to 0.7 microns. Yellow light wavelength is 580 +/- 15 nm, i.e. 0.565 to 0.595 microns.

Cloud, fog and mist droplets have a mean diameter of 10-15 microns.
Individual drops in any one rain cloud can be upto 100 micron dia.
And precipitated raindrops (actual rainfall) are 200 micron and bigger.

These are too big to selectively scatter light into constituent colors.
The entire visible spectrum from Violet to Red is barely 0.3 microns wide.

So there will be no color scatter. It makes no difference whether your fog lamp is yellow or white.

In fact, yellow light is achieved by having a yellow bulb or a yellow lens on the fog lamp. If anything, these attenuate, i.e., reduce the light coming through.

So yellow fog lamps serve no purpose. In fact modern fog lamps are no longer yellow.

Ram