Fog Lights?

[pissa]

What is the use of fog lights? or fog lamps. i was under the impression that they offered good visibility when driving in dense fog. however i see a lot of guys driving with fog lights on at colombo during night, and i seriously don't recall there being any fog in colombo ever! so do they offer better visibility in ordinary driving conditions as well? or are the purely used for decorative purposes?

[The Don]

  pissa said:

What is the use of fog lights? or fog lamps. i was under the impression that they offered good visibility when driving in dense fog. however i see a lot of guys driving with fog lights on at colombo during night, and i seriously don't recall there being any fog in colombo ever! so do they offer better visibility in ordinary driving conditions as well? or are the purely used for decorative purposes?

I am sure some use them for decorative purposes. But fog lights have one advantage in normal conditions which is that by law they should aim below the eye levels of other drivers, so you can use them to compliment long range visibility, when you are forced to use the low beam on normal headlights in consideration of other drivers coming towards you

[Ripper]

  The Don said:

I am sure some use them for decorative purposes. But fog lights have one advantage in normal conditions which is that by law they should aim below the eye levels of other drivers, so you can use them to compliment long range visibility, when you are forced to use the low beam on normal headlights in consideration of other drivers coming towards you

yep...some morons out there don't align their fog lights/driving lights properly and drive around like dons (no offense meant foe THE DON) without giving two hoots about others on the road...

Don't think even our cops know how to check and catch these fools...

Ideally only if visibility is bad due to environmental conditions, the fogs offer more luminance thanks to the high kelvin rated bulbs they use...but now with the invent of better bulb technology like HID's and high kelvin rated xenon bulbs etc... i doubt you get a huge advantage fog lights offered long years ago...

But in SL some folks are after the looks only and functionality goes outta the door...these buggers will go to any car accessories shop and buy those cheap chinese fog lights that don't even have a proper lens or a reflector and throws light all over the place and assume it's a fog light/driving light...

A land like no other indeed

[Pericles]

Just to clarify, FOG lights are yellow. This yellow light is what cuts thru the fog. The low mounted bright lights are driving lights. They do NOT help in the fog. I always use mine, and its not for show. In any case, N15s have the heads a little closer to the middle of the car, so an oncoming car might not realize how wide the car is. The driving lights are mounted a lot closer to the edges of the car.

Oh, and there are times when there is fog in Colombo. Rare tho. Generally early morning before the sun come up. Tho not so thick that you need to use fog lights.

[Ripper]

Interesting stuff

There is no good reason why fog lights are yellow. Here is an

excellent explanation provided by Professor Craig Bohren of Penn State

University:

"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 shortwavelength end of the visible

spectrum than at the longwavelength end. Lord Rayleigh showed this, didn't

he? Thus to obtain the greatest penentration 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 signalling 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."

Also, take a look at the following web site:

http://www.gi.alaska.edu/ScienceForum/ASF5/593.html

Dr. Lawrence D. Woolf

General Atomics

[Pericles]

Speaking as someone who has played around with fog lights and normal lights while driving upcountry in the thick mist, the yellow is better. I dunno about the penetration, but when you use white light, you get a lot of glare off the fog. Maybe the yellow is better coz it doesn't reflect and much and cause glare, despite its lower distance penetration? Coz as I recall, the dims are better to drive in the mist than the highs anyway.

Going a bit OT, but its an interesting topic.

[Ripper]

  Pericles said:

Speaking as someone who has played around with fog lights and normal lights while driving upcountry in the thick mist, the yellow is better. I dunno about the penetration, but when you use white light, you get a lot of glare off the fog. Maybe the yellow is better coz it doesn't reflect and much and cause glare, despite its lower distance penetration? Coz as I recall, the dims are better to drive in the mist than the highs anyway.

Going a bit OT, but its an interesting topic.

well IMHO i think it's one of those personal taste sorta thing than anything else... I've driven one my uncles cars with low placed hella fogs, 100w each and i didn't anything special over the normal PIAA's i've used before... In fact i think the PIAA's a did a better job just draining 55watts a bulb...

But then again this was not through heavy fog but in heavy downpours...

And i have noticed that even rally cars with loads of lighting power and even the ones that takes on misty routes are using white lights... In fact all the HID equipped performance lights meant for offroading etc are white...

at least i've not seen that many on tv or on the web...

Interesting topic machang... I'm on the opinion that yellow lights are just a fad without facts behind it...

[gunat]

My 2c worth- traditionally, i've relied on the fogs/driving lights to light up the ground immediately in front of the car over a wider crosssection, whereas the headlights are for front-distance visibility...

Found it particularly relevant on unknown-bad roads, so as to avoid any obstacles that aren't as obvious with the headlights.

My daily driving takes me out of Colombo on poorly lit roads- and with kamikaze objects such as dogs ('intercoolers' as Evilmak calls them), drunks/dumb people- i've found that fogs give that extra kudos with visibility. Probably not as relevant for colombo, except for potholes, perhaps.

I guess there is some degree of 'posing' that goes along with having your fogs on, as it differentiates your car from the average.i for one, take notice when i see a vehicle with the fogs on- just to see it may be.

[Ripper]

  gunat said:

My 2c worth- traditionally, i've relied on the fogs/driving lights to light up the ground immediately in front of the car over a wider crosssection, whereas the headlights are for front-distance visibility...

Found it particularly relevant on unknown-bad roads, so as to avoid any obstacles that aren't as obvious with the headlights.

My daily driving takes me out of Colombo on poorly lit roads- and with kamikaze objects such as dogs ('intercoolers' as Evilmak calls them), drunks/dumb people- i've found that fogs give that extra kudos with visibility. Probably not as relevant for colombo, except for potholes, perhaps.

I guess there is some degree of 'posing' that goes along with having your fogs on, as it differentiates your car from the average.i for one, take notice when i see a vehicle with the fogs on- just to see it may be.

totally agree about lighting up ground immediately in front of the car... i have gone into deep potholes cos my current light setup fails to properly light up that area on low beams unless i'm reall really paying attention to it...

But that's just quite tough on our roads cos you're already fighting a loosing battle trying to keep up with trishaws, mopeds, bicycles, drunkards, dogs, cats etc etc

Guess it's time a get some fog lights still prefer the white though

[Pericles]

  Ripper said:

Guess it's time a get some fog lights still prefer the white though

Driving lights macho.

[Ripper]

  Pericles said:

Driving lights macho.

No no i wanna call it FOG LIGHTS

on a serious note... why do you think all these rally folks are using white lights as opposed to yellow ones? I was highly curios about this who white/yellow things and did a few searches on www and it seems that most of the rally equipment people are even rally teams are using white lights...

strange

btw. how much of wattage can you dedicate to these fogs/driving lights from a stock electrical system? most of the fogs seems to be over 100w a piece

[Ripper]

from wikipedia

http://en.wikipedia.org/wiki/Automotive_lighting

Fog lamps

Front fog lamps provide a wide, bar-shaped beam of light with a sharp cutoff at the top, and are generally aimed and mounted low.[11][12][13] They may be either white or selective yellow. They are intended for use at low speed to increase the illumination directed towards the road surface and verges in conditions of poor visibility due to rain, fog, dust or snow. As such, they are often most effectively used in place of dipped-beam headlamps, reducing the glareback from fog or falling snow, although the legality varies by jurisdiction of using front fog lamps without low beam headlamps.

Use of the front fog lamps when visibility is not seriously reduced is often prohibited (for example in the United Kingdom), as they can cause increased glare to other drivers, particularly in wet pavement conditions, as well as harming the driver's own vision due to excessive foreground illumination.[14]

The respective purposes of front fog lamps and driving lamps are often confused, due in part to the misconcepion that fog lamps are necessarily selective yellow, while any auxiliary lamp that makes white light is a driving lamp. Automakers and aftermarket parts and accessories suppliers frequently refer interchangeably to "fog lamps" and "driving lamps" (or "fog/driving lamps"). In most countries, weather conditions rarely necessitate the use of fog lamps, and there is no legal requirement for them, so their primary purpose is frequently cosmetic. They are often available as optional extras or only on higher trim levels of many cars. Studies have shown that in North America more people inappropriately use their fog lamps in dry weather than use them properly in poor weather.[15]

[Pericles]

Rally ppl use the extra lights for night, not for fog. Like the wiki article you put states "They are intended for use at low speed to increase the illumination directed towards the road surface and verges in conditions of poor visibility due to rain, fog, dust or snow."

As for the rest, They say the purposes are confused, but don't state how to tell the difference. That would have been useful.

Anyway, what I have on mine are driving lights Right of pic.

http://autolanka.fotopic.net/p37811430.html

[miniace]

According to cops, Fog light in non-misty/foggy areas and more than two additional driving lights become a good source of income for them and for the Govt!

MINIACE

[lakshank]

Please dont get offended with me guys , coz its not mine okay !

Just thought its a nice one to share.

[Pericles]

  lakshank said:

Please dont get offended with me guys , coz its not mine okay !

Just thought its a nice one to share.

That top row is illegal. Cops really hate those things. Had a set of disconnected, covered lights on the pick-up, and they still had problems with them.

Uda-Walawe, by any chance?

[Ripper]

  lakshank said:

Please dont get offended with me guys , coz its not mine okay !

Just thought its a nice one to share.

the chic on the side or the first landy mate?

ok ok lame joke... nice jeep mate...agree with peri on the legal issue...as long as you're offroad it's ok i suppose

btw...those things must be draining a lot of power from your electricals i suppose

[lakshank]

Still my mate didnt hve any problems from cops for the lights. could be coz im always escorting him with my softtop.( behind this in the pic)

ha ha ripper...with all seriouness they both arent mine..okay.

Yes Peri...this is in uda walawe.... Can i be a propagandist in here for a moment.

www.de-olifant.net

try the link.. a fantastic place to be visited.

[Ripper]

  lakshank said:

Still my mate didnt hve any problems from cops for the lights. could be coz im always escorting him with my softtop.( behind this in the pic)

ha ha ripper...with all seriouness they both arent mine..okay.

Yes Peri...this is in uda walawe.... Can i be a propagandist in here for a moment.

www.de-olifant.net

try the link.. a fantastic place to be visited.

guess the landy fellows enjoy a bit more liberty from cops cos it takes a while to figure out that these are indeed not escort jeeps

I have given way to landies driven fast with lights on thinking it's a constipated minister bloke rushing to get the job done only to find out once it passes me for it to be a civilian one

The downside is that you also might get a cloud of high speed ball bearings heading your way if our feline outfit up north mistakenly think you are one of those undercover V*P's

[lakshank]

u r damn right. After that minister DM dassanayakes incident we came to a conclusion to give up this excorting business....infact they dont want to come behind me coz naturally people think this is a fleet that belongs to some V*P.. even if we drive slowly.

why blow the heads up? better use my mothers march and go at 20 mph.

[StarScream]

  miniace said:

According to cops, Fog light in non-misty/foggy areas and more than two additional driving lights become a good source of income for them and for the Govt!

MINIACE

Thats right. I have seen a ticket with a chap who had extra illumination in his car. Ticket stated "amathara pahan dalwa dawanaya kireema" .... i've always wondered if this was in that list of traffic offences in the ticket or something just made up to give a ticket which they are pretty sure wont be challenged in court. Anybody know if having extra illumination under the driving lights is illegal for sure?

[lakshank]

I once got caught for having a crash bar in my fathers mitsubishi van.(po25) It had a pair of original fog lamps too which are very yellowish. I got copped near “thorana handiya” for having them.

This is what was written on the ticket – “ Ishta roopa weta saha idiripasa amathara pahan”

I knew that having a crash bar is illegal but what the heck about lights. I thought the bugger is trying to make some money so I argued without knowing that he is the traffic OIC of paliyagoda police. It was kind of a verbal fight more than an argument.

When I went to collect my license with the post office receipt only I got to know that he is the big shot in traffic dept. He took the gazette out from a cupboard and started to teach me the rules.

“you cant have any lamps above the level of the vehicles main beams.”

I was dead silent and shrinking with all shyness coz he was shouting at me in front of all the other people. Now I know the rule and most importantly now I don’t go to argue with them.

[Ripper]

  lakshank said:

I once got caught for having a crash bar in my fathers mitsubishi van.(po25) It had a pair of original fog lamps too which are very yellowish. I got copped near “thorana handiya” for having them.

This is what was written on the ticket – “ Ishta roopa weta saha idiripasa amathara pahan”

I knew that having a crash bar is illegal but what the heck about lights. I thought the bugger is trying to make some money so I argued without knowing that he is the traffic OIC of paliyagoda police. It was kind of a verbal fight more than an argument.

When I went to collect my license with the post office receipt only I got to know that he is the big shot in traffic dept. He took the gazette out from a cupboard and started to teach me the rules.

“you cant have any lamps above the level of the vehicles main beams.”

I was dead silent and shrinking with all shyness coz he was shouting at me in front of all the other people. Now I know the rule and most importantly now I don’t go to argue with them.

OT...macho are you from that area

my parents are from kelaniya and i used to get caught quite a few times on my mobikes to peliyagoda cops

there was a traffic OIC bugger there, dark thin fella and you rarely get away from him by arguing...not even the usual monetary assistance will see you through the man

he's still there if i'm not wrong

Once i was stopped for pulling wheelies on the road and the cops shed there aren't any offences in their books for that but if i were to do it again and get caught, they'll be very creative with the whole thing...

And another instance i was kept by the roadside for about half an hour as punishment for zipping through a closing rail gate, near thorana junc. No tickets though

man the whole getting copped thing has so many bloody good stories we can have a new thread on it

[lakshank]

Yes ripper ..he is the bugger....his name is pushpakumara or something.the dark tall bugger. He kept my driving license in his own wallet coz he wanted to blast me.

by the way i am from malabe...but we go that way very frequently.

[fiat fan]

Holy thread resurrection Batman!

Ok guys jokes aside. I have a question.

 

What color fogs are best? Yellow, white(hid/xenon) or them new LEDs. 
 

I personally like the look of the yellow fogs and yellow seems kinder to the eyes.

Since Me and my family/friends seem to live under rocks and sleep with the stars,I prefer maximum usability and performance over energy consumption and looks.

New vehicles seem to come with all white-beam even on fogs though. My Q3 has halogen fogs inside the headlight(just like my b5), but they aren’t that strong or useful.

LEDs are super bright, but they seem to just washout the view and you dint really see full colors as they are. Also bloody expensive and seems to wear out fast. But I am willing to burn my cash if they are worth it. Needs expert opinions.

Fun fact- a guy told me use led because it increases fuel economy! Tf is wrong with people. Im guessing the change is very very very minimal, but he noticed it.

[iRage]

  On 9/11/2020 at 2:19 AM, fiat fan said:

Holy thread resurrection Batman!

Ok guys jokes aside. I have a question.

 

What color fogs are best? Yellow, white(hid/xenon) or them new LEDs. 
 

I personally like the look of the yellow fogs and yellow seems kinder to the eyes.

Since Me and my family/friends seem to live under rocks and sleep with the stars,I prefer maximum usability and performance over energy consumption and looks.

New vehicles seem to come with all white-beam even on fogs though. My Q3 has halogen fogs inside the headlight(just like my b5), but they aren’t that strong or useful.

LEDs are super bright, but they seem to just washout the view and you dint really see full colors as they are. Also bloody expensive and seems to wear out fast. But I am willing to burn my cash if they are worth it. Needs expert opinions.

Fun fact- a guy told me use led because it increases fuel economy! Tf is wrong with people. Im guessing the change is very very very minimal, but he noticed it.

Expand  

Well....yellow and white have reasons for them being those colours.

Yellow are FOG lights....Yellow light travels through and further in fog/mist (recollect the O and A Level physics lessons on light..). 

White light is for brighter illumination for added light whilst driving in dark environments and they are called Driving lights.

So technically fog lights are only yellow. This is also the reason why old school serious off roaders had both yellow and white lamps mounted on them.

So whether you need white or yellow lighting depends on the environment you will be driving in to sleep under the stars. 

Toyota was offering special discounts on their multimode bumper lights. They can be yellow, white or blue. Even with a discount they were pretty pricey.  I am sure you can get OEM ones that are the same and mounted on a bar or a metal bumper