Fog lamps - white or yellow?

snaronikar · 1st June 2008, 23:09

Just a Query: Is Yellow Fog Lamps still allowed? I thought these fog lamps are banned.

alpha1 · 2nd June 2008, 16:11

Hmmm, so now how does the Prof explain ppl's experience?

babaops · 10th February 2010, 17:29

Can anyone tell how important is it to have foglights with yellow beam againgst normal light during rainy/foggy time. Reason, I recently got my i10 fitted with OEM fog lamps and they are not yellow. I forgot to check this with them before installation.

Thad E Ginathom · 11th February 2010, 00:50

Quote:

Originally Posted by babaops

Can anyone tell how important is it to have foglights with yellow beam againgst normal light during rainy/foggy time. Reason, I recently got my i10 fitted with OEM fog lamps and they are not yellow. I forgot to check this with them before installation.

I thought yellow went out in about 1961! ?

I think the original theory was that it "cut through" the fog better than white, but I think that theory is no longer accepted.

There may be some idea that they dazzle oncoming traffic less, but that is not valid because front fog lights should be aimed well down at the road, and will not dazzle. (great for spotting potholes)

babaops · 11th February 2010, 12:54

Quote:

Originally Posted by Thad E Ginathom

I thought yellow went out in about 1961! ?

I think the original theory was that it "cut through" the fog better than white, but I think that theory is no longer accepted.

There may be some idea that they dazzle oncoming traffic less, but that is not valid because front fog lights should be aimed well down at the road, and will not dazzle. (great for spotting potholes)

thanks a lot for this info,but then why do we hear off and on that yellow light is good in such environmental conditions. Any clue on this?

sriturl · 11th February 2010, 14:32

Quote:

Originally Posted by babaops

thanks a lot for this info,but then why do we hear off and on that yellow light is good in such environmental conditions. Any clue on this?

As per what I remember from physics books long back is that yellow light offers more penetration through fog, and that is why you would still see sodium vapour lamps for street lights.

More info here...
Selective yellow - Wikipedia, the free encyclopedia

babaops · 11th February 2010, 20:41

so if I can concise both the comments from sriturl and Thad then would it be prudent to say that since fog light is aimed at the road so it can be the normal light, but head lights during fog should be yellow as they can penetrate better through fog.

Is my understanding correct?

vivekiny2k · 11th February 2010, 21:10

Fog lamps also help "others" see you well and respond in time. for that purpose yellow will serve better. but if used as a headlight, it will definitely dazzle others.

I think manufacturers decided to take a subtle approach and provided a regular light just enough to make your presence felt to other road users. For extreme cases like heavy fog and off roading in rural areas it still may be better to use yellow.

EDIT: I doubt if the purpose is to SEE the road with those lamps. You don't have to concentrate on road just because you are going slow

. You would be going fast on that road if not for the fog and would never care about the potholes.

Thad E Ginathom · 11th February 2010, 23:29

Well... I guess it may come down to faith. I have none in yellow fog lamps. They were all yellow in my UK childhood, although only the bigger posher cars had them, then they just stopped making them that way. Maybe because the theory got debunked; maybe because they wanted to save by not buying yellow colour glass. Not being a scientist, I do not know, but, as I say, my hunch is that yellow fog lights serve no purpose at all.

And I am sure the purpose of fog lights is to see the road immediately in front of you --- and you should be going so slowly that that is all that matters!

Potholes is another thing that I shouldn't have dragged into the fog topic!

Thad E Ginathom · 12th February 2010, 16:35

Now that the moderators have made a new thread for this topic it has been good to review the previous posts.

I believe (faith again

) that the answers are in post #7... there is no advantage to yellow light.

History comes around again and again, and people pick up old ideas, sometimes even with the same old justification.

babaops · 12th February 2010, 21:36

Thanks a lot for all the replies and to the Mods to move this mail chain to its proper place.

1st June 2008, 23:09	#16
snaronikar Senior - BHPian Join Date: Jun 2007 Location: Bengaluru Posts: 2,845 Thanked: 29 Times View My Garage	Just a Query: Is Yellow Fog Lamps still allowed? I thought these fog lamps are banned.
	() Thanks

2nd June 2008, 16:11	#17
alpha1 Senior - BHPian Join Date: Apr 2007 Location: LandOfNoWinters Posts: 2,093 Thanked: 2,604 Times	Hmmm, so now how does the Prof explain ppl's experience?
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10th February 2010, 17:29	#18
babaops BHPian Join Date: Sep 2009 Location: Bangalore Posts: 61 Thanked: 2 Times	Can anyone tell how important is it to have foglights with yellow beam againgst normal light during rainy/foggy time. Reason, I recently got my i10 fitted with OEM fog lamps and they are not yellow. I forgot to check this with them before installation.
	() Thanks

11th February 2010, 20:41	#22
babaops BHPian Join Date: Sep 2009 Location: Bangalore Posts: 61 Thanked: 2 Times	so if I can concise both the comments from sriturl and Thad then would it be prudent to say that since fog light is aimed at the road so it can be the normal light, but head lights during fog should be yellow as they can penetrate better through fog. Is my understanding correct?
	() Thanks

11th February 2010, 21:10	#23
vivekiny2k Senior - BHPian Join Date: Feb 2005 Location: cincinnati, jabalpur,chennai Posts: 1,264 Thanked: 209 Times View My Garage	Fog lamps also help "others" see you well and respond in time. for that purpose yellow will serve better. but if used as a headlight, it will definitely dazzle others. I think manufacturers decided to take a subtle approach and provided a regular light just enough to make your presence felt to other road users. For extreme cases like heavy fog and off roading in rural areas it still may be better to use yellow. EDIT: I doubt if the purpose is to SEE the road with those lamps. You don't have to concentrate on road just because you are going slow . You would be going fast on that road if not for the fog and would never care about the potholes. Last edited by vivekiny2k : 11th February 2010 at 21:13.
	() Thanks

11th February 2010, 23:29	#24
Thad E Ginathom Distinguished - BHPian Join Date: Jun 2007 Location: Chennai Posts: 11,004 Thanked: 26,428 Times	Well... I guess it may come down to faith. I have none in yellow fog lamps. They were all yellow in my UK childhood, although only the bigger posher cars had them, then they just stopped making them that way. Maybe because the theory got debunked; maybe because they wanted to save by not buying yellow colour glass. Not being a scientist, I do not know, but, as I say, my hunch is that yellow fog lights serve no purpose at all. And I am sure the purpose of fog lights is to see the road immediately in front of you --- and you should be going so slowly that that is all that matters! Potholes is another thing that I shouldn't have dragged into the fog topic!
	() Thanks

12th February 2010, 16:35	#25
Thad E Ginathom Distinguished - BHPian Join Date: Jun 2007 Location: Chennai Posts: 11,004 Thanked: 26,428 Times	Now that the moderators have made a new thread for this topic it has been good to review the previous posts. I believe (faith again ) that the answers are in post #7... there is no advantage to yellow light. History comes around again and again, and people pick up old ideas, sometimes even with the same old justification.
	() Thanks

12th February 2010, 21:36	#26
babaops BHPian Join Date: Sep 2009 Location: Bangalore Posts: 61 Thanked: 2 Times	Thanks a lot for all the replies and to the Mods to move this mail chain to its proper place.
	() Thanks