http://forums.audiworld.com/a4gen2/msgs/440820.phtml

Please help me prove to this guy that the 6000k bulbs aren't "brighter" than the 4100k bulbs. From the FAQ and specsheets, It is clear that 4100k bulbs have greater lumens than the 6000k bulbs. This guy is gettin annoying, although he does have some valid points, I think he is just using them incorrectly.

EDIT: also, Is there a spec sheet for the ultinons? I remember seeing on a while back, I know there is a spec sheet for the regular bulbs (it right there on the FAQ).

TIA.

His points only really apply to halogen bulbs.

HID bulbs work on a completely different scale.

~A

he has everything right up till "Anything beyond that is either ultraviolet or infared." after that..
his conclusions need some work. in the end, he needs a physics book more than a chem book.

light intensity depends on how much energy is released, but the Color of light has no direct correlation to how Bright (the energy being released) a light source is. yes, it is possible that the ultinions Are producing more heat/energy, however most of it is unusable due to the color or wavelength it is being presented in. shorter wavelengths have a tendency to scatter and not reflect back, thus not returning any information to the viewer. think of a radar dish, with only a fraction of its radio signals returning back. doesn't matter How much power it has if it recieves little or no signal or has no range.

brightness is a relative term used by people to determine how much Useable light is available for the naked eye to use. it has been determined long ago that color closer to the yellow/orange/red is easiest/most effective on the human eye. (which is why Most street lights are orange etc..) which in turn means that less intensity is needed to produce the greater effect.

if that is his argument to using 6000k bulbs, let him. you and i will see the deer trying to jump across the freeway and avoid it. he'll.. who knows? =)

Do you mind if I copy and paste that to stick it to him?

Thanx a whole bunch in advance. =)

The textbook lecture is right on. His layman terms are totally inaccurate.

The color of light is measured in degrees kelvin, but have nothing to do with energy emitted because of color temperature, nor does it have anything to do with more brightness associated with that ewnergy increase.

While yes, 5800K or 6000K color temperature approaches the daylight color of bright noon sunlight much closer than 4100K, brightness is still measured in lumens, and fact is 4100K gives off 3200-3500 lumens, while 6000K gives off 2600 lumens. On HID bulbs that is.

How bright the objects we see on the road appear to our eyes is a matter of how much of our projected color is absorbed by those objects and how much is reflected back to us. That's a whole different story.

If a halogen 3200K bulb was able to put off 4000 lumens, it would be BRIGTHER than an OEM 4100K at 3200 lumens, and we would have much greater vision at night. It would also put off tremendous amounts of heat and would consume tremendous amounts of power.

If, on the other hand, the ultinon 6000K bulb was able to produce the 3200-3500 lumens of the OEM 4100K at ITS color temperature, we wouild probably be able to see better under most road conditions since its color temperature is closer to bright noon daylight. OEM uses 4100K because it is "the best bang for the buck". More lumens for less watts, period.

I hope you don't mind me pasting some parts of what you typed to tell to him.

Heck no I know I'm right. I remember my physics classes in college for my engineering degree, and could also look for some internet sites with that very same info. It's not a new discovery, just a matter of whether you know it or not.

Also, the the definition of CRI (Color Rendering Index) explains alot around the fact regards to useful light. Not much used on automotive lighting sites (if at all), but its used in all sorts of data sheet for home and commercial lighting:

http://www.brite-lite.com/Products/Technical/Color_Temp.html

Someone should just paste him this whole link to this forum string.

Slackyaw said it pretty good. A 35 watt Ultinon still releases 35w worth of light energy, but since the 'lumen' measurement is a brightness measurement taken at the center of the human's visible spectrum, then the Ultinon has a lower lumnetic value, since more of that energy it releases is outside of the human's visible spectrum. Just like a 15,000k UV blacklight that is using say, the same 35 watts of electricity, will look very very dim since you can't see a lot of it's light energy emission, but if you put that blacklight into a room with white paint on the walls high in phosphors, then the walls will light up very very bright when you see the light source's reflection through it, since the phosphorous paint changes the wavelength back to the visible level within the human's perception. In fact, with real Ultinons in your car driving at night, certain objects high in phosphors tend to reflect the light back at you very bright, as this is that same phenomenon. 4100k bulbs still do a little of this, but since there is more actual output within the visible spectrum, then you have more direct light that the human can see reflecting off of all things, phosphorous or not.

Years and years ago, the whole color temp thing originally started as to be a real representation of how hot a piece of metal glows based on temp and the color it changes to, but since then, the standard has been changed. They now just use it as a standard to compare colors of light, because with gas discharge, they can put different gasses, and different mixtures of salt, or metals, to obtain any color they want at a given power range. That guy simply needs to read up on color temp, and how they came up with the standard, and how it has evoloved into the measurement that it is today. I can still take my cutting torch and heat up a piece of metal til it glows red, then yellow, then hotter til it's white, then hotter til it's blue at the core of the heat where the center of the flame is, and that means I've excited those atoms with a LOT of energy, but a lot of that energy is not in human's visble range of perception (which corresponds to why a welder must wear UV protective googles or a welding mask while welding or cutting metals- since UV rays are damaging to the eye). But this was why the 'lumen' figure was invented, to give people an accurate way to tell how bright light was within OUR range. Now the Predator, he sees in a different range like infrared or something, so lumens wouldn't be the best measurement for him to use.

Also, by the way, UV is light energy that is on the voilet end of the light spectrum, and infrared is on the opposite end, below the red color spectrum. Infrared is mostly heat energy. When you first start to heat a piece of metal with a torch, the first thing you feel of it's energy is heat (which is infrared energy which you cannot see but you can ony feel it's emission), then when you keep the torch on it (transferring more energy to it), it starts to emit visible energy which looks red and then orange in color, etc. Then UV is at the OTHER end of the spectrum, as that guy on the Audi forum was kinda implying that they were right next to each other in the UV end of the spectrum or something?

there's a lot of terminology that overlaps in chem and physics. he's got a few of them crossed.

if you really wanna bug him, ask him why sunlight, (which is THE most energy abundant source we can just LOOK at with the naked eye) looks more orange / yellowish than purple. not saying there isn't any purple in there.. but u get the idea. (smog doesn't count)

there's also the whole millions of years of evolution which has adapted our eyes to the best kind of light for the human eye to see in, if purple really was the better color, we'd see everything in a more purple color as our eyes would've adapted to incorporate more of it in how we see.

screw afterthought, it'll only get me in trouble. hehe =)
just ask the guy if he really wants a bulb that's so much "Hotter" in a plastic housing. i personally don't.

The brighter a source is, the human eye percepts the color as being more yellow. 5500k shining at you at 2500 lumens looks very blue, but 5500k at the Sun's level of output looks yellower. We had a HUGE discussion about this a couple years ago on the Philips Lighting Forum. It's something to do with the rods and cones in your eye, and at varying intensities will change your perception of colors. I could dig it up and talk all about it again, but I'd have to dig around all the articles and find the scientific data to back it again. I remember H1HID was into that old dicussion as well, maybe he remembers the details? All I know is that this holds true, because at night HIDs always look way bluer from far far away because the intensity is way dimmer to you looking at it, but when you get closer and closer, the color looks more yellow and yellower the brighter it gets to your eyes. Observe it next time and you'll see it too. For the same reason, the Sun looks yellow. Our discussion I remember had also even evolved into why the Sun then looks way amber on the horizon in the rising and setting, and that has to do with how the sharp angle angle the light of the Sun has to shine through the atmosphere during rising/setting (making the atmoshere effectively thicker) which filters out much of the light going through it leaving mostly IR energy and energy in the lower part of the spectrum, but higher spectrum and UV light is mostly filtered out at sharp angles going through the atmosphere.

All this said by Heman, Josch, and Slackjaw is correct. I just found some links for substantiation. See here

http://imagers.gsfc.nasa.gov/ems/visible.html


This site is also particularly good if yo have the time. Main simple thing is: Don't mix brightness with color temperature. My guess is bulbs should be denominated such as: "3200 lumens bright at 4100K color temperature" or something of the sort.

http://www.glenbrook.k12.il.us/gbssci/phys/Class/light/u12l2c.html