[snj49er]

Squidly -- Light with a continuous spectrum (i.e., sun, tungsten) has a "color temperature". Light with a non-continuous or spikey spectrum (HID, LED, fluorescent, etc) has a "correlated color temperature". The first pair of graphs shows spectral power distributions for sunlight on the left and an unidentified LED on the right. The next graph is the SPD of a 5500K HID lamp. While they may all create a similar visual effect, they're made up of very different spectral energy and the correlated color temps are approximations.

The human eye has different sensitivity across the visible range as in the last graph. Since it is high in the yellow/green range, light that is heavily weighted towards blue and/or red will not appear to be as bright. Instruments that measure lux and lumens take this into account. Those that measure spectral energy or radiant flux do not.

So if a light has a higher CT or CCT which is moving the energy out of the range of highest human sensitivity, it will take more power to maintain the same apparent brightness. For example, I have some 400 watt 20,000K lights that do not look very bright at all, but they are cranking out some serious radiant energy.

[Jason954x]

Originally Posted by stormlv

So I've watched many threads passing by, with people asking whether or not the LEDs are worth it over Xenons.
Those threads always derailed with arguments that one is better than the other, but none backed up their claims.

Anyway, my car was in the shop (following an accident - then again following dealer fuckery) and I got it back today.
In the mean time I was given a 320xi with Xenons.

Here are some picture comparisons between the loaner's Xenons and my LEDs (both adaptive lights)

First of all:
- pictures were taken at the same distance, with the same camera and lens (Sony A7 with the Zeiss 55mm F/1.8)
- all picture had the exact same exposure : 1/5 seconds
- all picture had the exact same F stop : F/5.6
- all picture had the exact same ISO : 100
- the only processing that I did was to convert Sony ARW to 16bit tiff
- for the numerical analysis I converted all the pictures to B&W
- garage in front was @ around 5-7m
- I can provide the RAW files from my camera if anyone's interested. If not I got the jpegs on flickr

Xenon Low beams vs LED Low beams


In this comparison I noticed that the LEDs are brighter. One can see this in the amount of light that falls on the door itself and the floor.
I've did some very simple numerical analysis on these photos (converted in B&W). These are 16bit photos, so max numerical values go to 65535.

Xenon: pixel average* for whole photo: 5578
LED: pixel average for whole photo: 7162
*by pixel average I mean, the average value of all the pixels in the image.

Xenon: pixel average for the dark* part of photo: 1978
LED: pixel average for the dark* part of photo: 1857
* dark part = top region, not illuminated by the headlights. Basically used to measure ambient light in the garage.

Xenon: pixel average for the lit* part of photo: 11542
LED: pixel average for the lit* part of photo: 15958
*lit part = bottom region, illuminated by the headlights. Gives a measure of the strength of the low beams

By these numbers alone: LEDs low beam gives 38% more light

Xenon High beams vs LED High beams


Here, the first thing you'll notice is that the illuminating pattern is different.
I don't know how that would translate in real life visibility though. I wasn't inspired, at the time, to take photos of targets illuminated at 100-200m ahead...

If we get to the business of power output, here again I say that the LEDs win out.
You can definitely see the two beam centers which just "light" up with the LEDs.

And here are some numbers to back up the claims:

Xenon: pixel average for whole photo: 12981
LED: pixel average for whole photo: 15312

Xenon: pixel average for the dark* part of photo: 2197
LED: pixel average for the dark* part of photo: 2094
* dark part = top region, not illuminated by the headlights. Basically used to measure ambient light in the garage.

Xenon: pixel average for the lit* part of photo: 19714
LED: pixel average for the lit* part of photo: 25822
*lit part = bottom region, illuminated by the headlights. Gives a measure of the strength of the high beams

By these numbers alone: LEDs high beam gives 30%** more light. Here, I included the dark middle region of the Xenons, so that number is probably closer to 20%.

Here's my Flickr account for the full size photos: https://www.flickr.com/photos/stormlv/

Seems like you put some effort into this justification but "it shouldn't take all day for you to recognize sunshine". From my first night of driving with the LED I knew it was a better light source and I wouldn't go back to xenon/HID, but that's just my opinion. Regardless of statistics people will always choose what they think works for them.

[Mauricio Palacios. MD]

LED Vs. Xenon Lighting

Current light bulb technology has greatly improved over older incandescent bulb technology. Newer LED and xenon bulbs produce a more light while using less energy. The use of LED and xenon bulbs in flashlights and car headlights is common. You also can use LED and xenon bulbs in a variety of places, including under-cabinet lights, display lights and decorative lighting for holidays.

Light-emitting diode, or LED, lights use about one-seventh the energy of an incandescent bulb and can last up to 100,000 hours per bulb, according to G. Miller and Scott Spoolman in “Environmental Science Problems, Concepts and Solutions.” LED lights use a diode that is about one-fourth of an inch to convert electricity into light, according to the website toolbase.

Xenon Lights
Xenon technology uses the noble gas xenon to produce light that is very close to natural sunlight. Xenon headlights in cars improve visibility because the lights illuminate a broader area in front of the car than a traditional headlight. There are a variety of other uses for xenon lights, ranging from operating rooms to airport signal lights, because xenon bulbs last a long time, according to the Xenon Corporation.

Advantages of Xenon
The light produced by xenon gas technology is very bright, making it especially good for places like hospital operating rooms. It also is very close to natural light. Xenon gas lights can last from 6,000 to 20,000 hours per bulb, according to the website lighting-fixtures-tips-designs.

Disadvantages
Both xenon and LED lights have disadvantages. Xenon lights can explode when they are old, according to the website FilmTech. Xenon headlights can make it difficult for oncoming drivers to see, according to USA Today. LED lights produce directional light, but they don't create enough light to light a room. Xenon bulbs also are much more expensive than either LED or traditional lights.

http://www.livestrong.com/article/18...enon-lighting/

So, I think it's once again, only a matter of cost/benefit...

LEDs are cheaper to produce for BMW (AL, Hella) and they can sell that technology as "the ultimate". So... Here we go as beef cattle to the slaughter... Haha... I have 2 vehicles with OEM LED technology and other 3 with OEM HID Xenon technology. I think HID's are still better...

Lower production costs, less government regulations (in Europe, LED headlights don't have to equip headlights washers or automatic leveling control, because they emit less light, so less chance to disturb other drivers on the road) = cheaper - no more, no less...

[squidlyboy]

Originally Posted by rolltidef32

Very impressive Squidlyboy. I've often wondered if LEDs were worth the cost of upgrade for BMW.

Have been very impressed with xenon for several years, but do like to follow the flow of technology.

Following your analysis, would you opt for LEDs next time you buy?

I'm not against LEDs (most of my auxiliary lights are LEDs), but for the low-beams, I personally like xenon's because of the projectors - the spherical shape of the orb/lens make them look sexier and cleaner/classier IMO, and they focus the light, giving a much sharper cut-off. I haven't seen LEDs mounted behind projectors yet.

But to be honest, both LEDs and Xenons provide such a HUGE amount of output (difference) over halogens, that going with either one is a huge win.

[squidlyboy]

Originally Posted by snj49er

So if a light has a higher CT or CCT which is moving the energy out of the range of highest human sensitivity, it will take more power to maintain the same apparent brightness. For example, I have some 400 watt 20,000K lights that do not look very bright at all, but they are cranking out some serious radiant energy.

Thank you. Nice analysis.

I first discovered this phenomena when i replaced my OEM "4300k" halogen bulbs with one of those halogens with a blue filter around it, giving it an "effective" high color temperature. I was after a whiter color. To my dismay, i noticed i could hardly see anything on the road. Higher color temp, less lumens.

I then replaced it with another blue-filtered halogen bulb that claimed to be whiter AND provide more output. While it was indeed white, and the output was about 25%-30% brighter (more output), i found that that they changed the internal manufacturing of the bulb and were driving it so hard that the effective lifetime of the bulb was only rated to be half of what the OEM bulb was rate.

The lesson of the story?

1. Whiter Color (increased Color Temp)
2. More Output (increased Lumens)
3. Longer Bulb Lifetime

Pick any two... you don't get all three

[Mauricio Palacios. MD]

I think it's once again, only a matter of money (cost/benefit)...

LEDs are cheaper to produce for BMW (AL, Hella) and they can sell that technology as "the ultimate". So... Here we go as beef cattle to the slaughter... Haha... I have 2 vehicles with OEM LED technology and other 3 with OEM HID Xenon technology. I think HID's are still better...

Lower production costs, less government regulations (in Europe, LED headlights don't have to equip headlights washers or automatic leveling control, because they emit less light than HIDs, so less chance to disturb other drivers on the road) = cheaper - no more, no less...

[Billfitz]

Originally Posted by Mauricio Palacios. MD

in Europe, LED headlights don't have to equip headlights washers or automatic leveling control, because they emit less light than HIDs, so less chance to disturb other drivers on the road) = cheaper - no more, no less...

The reason for washers with HID is that a dirty lens can refract light upward into the eyes of on-coming drivers. It's not as much a concern with lower lumens output sources.

[snj49er]

Originally Posted by squidlyboy

Thank you. Nice analysis.

I first discovered this phenomena when i replaced my OEM "4300k" halogen bulbs with one of those halogens with a blue filter around it, giving it an "effective" high color temperature. I was after a whiter color. To my dismay, i noticed i could hardly see anything on the road. Higher color temp, less lumens.

I then replaced it with another blue-filtered halogen bulb that claimed to be whiter AND provide more output. While it was indeed white, and the output was about 25%-30% brighter (more output), i found that that they changed the internal manufacturing of the bulb and were driving it so hard that the effective lifetime of the bulb was only rated to be half of what the OEM bulb was rate.

The lesson of the story?

1. Whiter Color (increased Color Temp)
2. More Output (increased Lumens)
3. Longer Bulb Lifetime

Pick any two... you don't get all three

Yeah, it's kind of a double-edged problem. Once you start filtering out light to change the color, there's going to be less overall brightness...and what's left is going to be in the spectrum where the eye is less sensitive.

The engineering for HID bulbs with native color temps from 2,800-20,000K has already been done for other industries. There's probably not near enough demand to adapt that for those of us who would like bluer headlights.

[Mauricio Palacios. MD]

Originally Posted by Billfitz

The reason for washers with HID is that a dirty lens can refract light upward into the eyes of on-coming drivers. It's not as much a concern with lower lumens output sources.

Do you refer to the polycarbonate plastic? Is there another material in LEDs headlights cover? Dust never touches the lenses inside the HID units...

"In relation to headlights, the ADRs dictate the size and shape of a car headlight’s beam, as well as the maximum amount of permissible glare to oncoming traffic. For headlights with an output over 2000 lumens (that’s all HID units, basically) a headlamp washer and self levelling system is required, and cars sold with halogen/led lights usually aren’t equipped with either feature."

So:

HIDs > 2000 lumens
LEDs < 2000 lumens

Also interesting:

http://greyhead.co.uk/are-aftermarke...egal-in-the-uk

[Mauricio Palacios. MD]

http://www.autoevolution.com/news/ba...led-26530.html

[Billfitz]

Originally Posted by Mauricio Palacios. MD

Do you refer to the polycarbonate plastic?

The outside of the lamp, where it gets washed. When dirt builds up there light from the element gets scattered in all directions, including upward. With the very high lumens output of HID it's crucial to keep the lens clean so that won't happen. Of course, even with standard bulbs you want the lens kept clean, otherwise it's harder for you to see where you're going. I have my paint sealed, so it's easy to wipe the car free of dust and dirt whenever I see any buildup. When I do I clean all the lenses as well.

[stormlv]

I'm really starting to regret starting this tread

Anywho, I just wanted to reply to squidlyboy

Originally Posted by squidlyboy

And the real/bigger concern is that people casually reading this thread will walk away with the impression that LEDs universally provide more output than Xenons, which is simply not true, when there is so much more involved to making that type of assertion.

You're right in that one could come to that impression by quickly skimming through the thread. That was not my intention, and honestly I thought the point of the thread was quite obvious: compare BMW's LED and Xenon implementation, on two similar cars, of the same generation.

In any case, next time I'll bring a lux meter and do the measurements - maybe then there won't be so much controversy.

Lastly, after going through a few loaners until now (2s, 3s, 4s, and 5s) I still prefer the LEDs. To me they do seem brighter (which is what made me do the test in the first place). That said, test drive both cars and decide for yourselves before getting one option or the other.

[squidlyboy]

I get where you were coming from comparing the stock BMW LEDs vs BMW stock Xenons. The time and effort you took to produce that analysis was actually pretty remarkable, so kudos to you bro

It was more some of the casual comments that came in response to your OP that was a little more concerning - e.g. "well, i guess that proves it", or "cased closed", and "now we can all go out and buy based on data"

[rking117]

the only thing left to make sure we are talking apple to apples is a control photo. If you had taken a photo of the door using only a flashlight to illuminate a spot on the door that would not impact the light given off by the vehicle in any of the scenarios, obtain the mean average of that light across each photo then we could determine the exact brightness variation by type of light. The photos appear the same but small variations in the camera may cause a flux in light via aperture. Without getting so scientific about it good job on this one.

[Daftasabrush]

What I'd like to see is a comparison of the LCI 3 series LED and the 4 series LED. I've noticed that 4 series drivers tend to prefer LED over Xenon but 3 series drivers (myself included) would err towards Xenon over LED (although I think my LEDs have increased in brightness over the last couple of thousand miles).

[openwheelracing]

Current LED owner, previous Xenon owner (3 times).

I prefer the Xenons. However LED is a decent alternative considering Xenons are not even an option anymore.

The key though imo, is the projector.

[oonowindoo]

After having the LED on the F36 for 6k miles, my original observation is still valid:

There is no definite answer when it comes to LED vs HID because the best LED (with projectors) is better than the Worst HID. Or the best HID is better than most of the LEDs. So really depends on the cars.

LED is brighter and looks cooler but the problem is its range and width.

As far as my F36's LED it is bright but it is suffering the same problem as the 1990s reflector type of housing because it is a reflector type of Headlight. Reminds me of putting HID kit in a Halogen Non Projector housing.
I think with dual projectors + LED, it will solve a lot of the complaints i have but I don't have any projectors, so i would not know for sure.

[Squddie]

stormlv, can you give us the EXIF info for the photos?

That way we can see absolute brightness levels in case the camera software decided on different exposure.

[stormlv]

Originally Posted by Squddie

stormlv, can you give us the EXIF info for the photos?

That way we can see absolute brightness levels in case the camera software decided on different exposure.

Hey, I've temporarily allowed non friends on Flickr to view the Exif of the photos

That said, the brightness value will necessarily be different between the photos, since the average illumination will be different.

Here are the photos: https://www.flickr.com/search/?user_...ing&view_all=1

But IMO, I would just leave this thread to die

[shoguniori31]

Originally Posted by FC4

Cool.

Still not worth $1900.

i agree lol

[xdnbc]

Originally Posted by Philipangoo

I guess my real question should be, why is there even 3 head light options for the 3/4 series. Yet there is only 1 standard headlight option for a new Corolla..LED lights only.

And this is not me praising Toyota, they have tons of other new models that are offered that do not even have LED light option.

Why on earth are there still optioned out 45k-55k 3 series cars with Halogen lights.

Wouldn't reducing the offering to only LED light option reduce the overhead, planning, and supply chain logistics that comes with offering 3 completely different options?

I think LED lights are great, my buddy has the new Corolla that he DDs instead of his E90 M3, and those lights are so nice. I think safety is always a no brainer when optioning out cars. I also test drove a X3 my wife was interested in with LED lights, those were fantastic. Keep in mind for these cars this is not only a 1900 option, but also its an upgrade on top of lighting package which the lower trims have to order a la carte.

I just received my 2016 LCI 3 Touring and it comes only with LED lights in Canada.