4300K vs 5500K for vision in all conditions?

[JHZR2]

It seems pretty well established that OEM HIDs are 4300K, FWIW. For example, the bi xenon headlights in my 135i.

Audi has stated the following about their LED headlights:
Quote:
Full LED headlights produce light at 5,500 Kelvin, that's roughly the same as daylight. This could help your eyes perceive more contrast. They experience less strain. And those dark stretches of road become a little less daunting.
https://www.audiusa.com/technology/design/LED

My impression was that the yellower the light, i.e. closer to the 3600-ish K of a halogen, the better it does in inclement weather and especially rainy or foggy weather. That's the reason why the driving lights, in my w123 MB diesels, for example, are yellow, and why the French DOT required a yellowish tinge to their headlights for a while... Or so I hear...

I also understand that anything much past 5500K, or maybe even past 5000K is too blue and itoo easily lost in all but the best conditions... And that the light starts to tend towards blue and then purple, almost as a vanity color without much benefit optically at all.

So what is the sweet spot? Is it 4000-5000K? 5500K?

It just seems like the claims are more salesy than anything else, and something or nothing is better. The way I look at it, OEMs must have done some research... And they could have tuned HIDs from long ago to be more like 5500K if that was a better temperature.

Or perhaps it is a better temperature, but the chemistry of HID isnt as optimal at 5500K as it is at 4300K for longevity?

Thoughts?

 

[Kamele0N]

Osram Xenarc has 4150K....

When instaled in normal (non xenon) lights they glow (for the police) as normal H7 light...but you have much better visibility on the road...

So I will say... 4100-4200K is my sweet spot

 

[Kamele0N]

Phillips Xenon lights have 4300K...that is more towards blue/white...

 

[JHZR2]

Well I know nothing of this company or their product, but their explanation of the various ranges seems logical:

http://headlightretrofits.com/bulbs-info/hid-kelvin-color/

Still, VW is now claiming that 5500K is better for the eyes? Is that sales, new research, a fundamental characteristic that LED enabled that HID was dubious at, or what???

 

[Kamele0N]

Maybe it is better in normal driving conditions....on a dry road....with full moon on the sky without clouds

Show me that vw article about kelvins...

 

[Kamele0N]

And....you are compareing two completly different things...

Xenon vs LED

look at lumen output at 5000k Xenon vs 5500K LED...

I am not an expert...but I think that there can be a huge difference...

 

[eljefino]

I hope they have enough Color Rendition Index to light up red stop signs and reflectors properly.

I stuck a cheap white LED in my CHMSL housing and its output was a sickly pink-orange instead of perky red.

 

[Olas]

It comes down to personal preference, we all have different eyes and some are more sensitive to a given frequency than others..

I favour 3400k

 

[JHZR2]

Originally Posted By: Olas
It comes down to personal preference, we all have different eyes and some are more sensitive to a given frequency than others..

I favour 3400k


What you favor isnt what the OEMs provide. OEM HID is like 4300K and Audi is claiming 5500K is better for their LEDs (possibly because they cant make LEDs with lower color temperature?)

My interest here is in research or practical reasoning behind why these things are what they are.

Originally Posted By: Kamele0N

Show me that vw article about kelvins...


The link to the VW/Audi website was in my OP. It is stated there clearly and I quoted it too.

 

[JHZR2]

Originally Posted By: eljefino
I hope they have enough Color Rendition Index to light up red stop signs and reflectors properly.

I stuck a cheap white LED in my CHMSL housing and its output was a sickly pink-orange instead of perky red.


One would think that OE LEDs would need some sort of DOT approval which would mandate that?

I know the LED DRLs on my accord hybrid light up the road pretty well, even if they arent "bright".

 

[JHZR2]

Originally Posted By: Kamele0N
And....you are compareing two completly different things...

Xenon vs LED

look at lumen output at 5000k Xenon vs 5500K LED...

I am not an expert...but I think that there can be a huge difference...


If you normalized two light sources to provide the same number of lumens, and if the color temperature were the same (say, 5500K HID vs 5500K LED, both of which are available so notionally OEMs could obtain them, buy them, implement them, etc), notionally the illumination of the road would be the same (unless CRI comes into play perhaps as was mentioned).

Heck, forget LED vs HID... Lets just stick to one... 4300K OEM HID vs 5500K HID. You can get either. Which is better from an optical perspective and why? Why did OEMs select 4300K and not 5500K for HID? Why are they selecting 5500K for LED (per the audi article, and a recent LED headlight equipped Honda accord that I crossed paths with also has extremely white light, moreso than my 4300K OE HIDs in my 135i).

 

[eljefino]

Assuming it takes dozens of LED drivers they could "pepper in" a couple yellows or reds to warm them up a little. Let the optics diffuse it in.

 

[Jimzz]

Originally Posted By: JHZR2
Well I know nothing of this company or their product, but their explanation of the various ranges seems logical:

http://headlightretrofits.com/bulbs-info/hid-kelvin-color/

Still, VW is now claiming that 5500K is better for the eyes? Is that sales, new research, a fundamental characteristic that LED enabled that HID was dubious at, or what???



If you believe anything VW/Audi has to say I have a bridge i'll sell ya.

VW/Audi "Our cars are reliable now...", "Our cars are green and great for the environment...", "5500k is the new 4300k...", etc...

 

[HerrStig]

AS usual, here in the highly informed USA the "bigger number is always "better". French "yellow" is produced by filtering out BLUE light which contributes to glare. The French by agreement stopped requiring yellow when they joined the EU, however they did NOT ban the use of yellow on French roads. The downside of yellow filters is that total light output is reduced for the same bulb. I've found properly filtered yellow fog lights to provide better contrast in rain and snow.

 

[UG_Passat]

Back then, the French stopped using their yellow coating, because it contained Cadmium, extremely toxic, and the EU was starting to clamp down on certain environmental hazards.

Much of the "3000K" bulbs for HID uses a "dichroic" filter, is not the same as selective yellow, and can cause off-axis glare.

Osram Cool Blue Intense 5000K AND 3400 lumens. Many vehicles were getting the CBI bulbs as the factory bulbs, instead of the older 4150K bulbs.

 

[Cujet]

My Jaguar had 6000K HID's in each projector. The view was good, plenty bright, but not particularly pleasing. The 6000K bulbs produce a grey-blue light. Grass, for example, looks off color.

One bulb failed and I replaced it with a 4300K bulb. Much better in my opinion. Especially on rainy nights on rural back roads.

 

[Olas]

Originally Posted By: JHZR2
Originally Posted By: Olas
It comes down to personal preference, we all have different eyes and some are more sensitive to a given frequency than others..

I favour 3400k


What you favor isnt what the OEMs provide...


I don't claim to know any better than OEMs, but I know what my eyes prefer regards contrast and glare.

The 5k and higher look, IMO, is purely vanity.

 

[HTSS_TR]

Originally Posted By: JHZR2
What you favor isnt what the OEMs provide. OEM HID is like 4300K and Audi is claiming 5500K is better for their LEDs (possibly because they cant make LEDs with lower color temperature?)

My interest here is in research or practical reasoning behind why these things are what they are.

Back when the HID first available in mid/late 1990's the technology was able to do 4300K only, but lately they had been able to do around 5000K(I think Osram Cool Blue Intense is one of them) and newer high end cars(Lexus LS460 ?) came with 5000K HID too.

 

[SubLGT]

Originally Posted By: JHZR2
….So what is the sweet spot? Is it 4000-5000K? 5500K?...


You might find the following discussion interesting:

http://www.candlepowerforums.com/vb/show...-color-spectrum

 

[JHZR2]

Originally Posted By: SubLGT

You might find the following discussion interesting:

http://www.candlepowerforums.com/vb/show...-color-spectrum


Interesting...

Quote:
It's been found that LED vehicle headlamps create the sense/feeling/impression of "brighter" light, and it's been found that they give poorer seeing performance compared to halogen lamps of equal intensity ... It's been found that for equal intensity, higher-CCT white headlights create significantly higher discomfort glare without an accompanying improvement in seeing, and that lower-CCT white headlights create significantly lower discomfort glare without an accompanying degradation in seeing. ... There is a strong marketing/PR push towards "whiter" light (a more or less meaningless term most often referring to light that is bluer/has a higher CCT). The trope line is "Closer to natural daylight", though of course that is true only in the superficial, relatively trivial sense of apparent light color (CCT). The SPD of a metal halide lamp (such as an automotive HID headlamp) bears little resemblance to the SPD of sunlight.