Halogen vs. LED headlight : a direct comparison beamshots

Found this very interresting on a Prius Specialized forum. Two Prius 2010 are in direct comparison, one with the standard Halogen headlight, the other with the optionnal LED headlight. Both are stock from Toyota...

SEE THE PICS HERE

While the LED equiped car is further away from the target, see how the illumination is imploved

This is very impressive IMO

The white point is too high with the LEDs.
Far too blue.

Whenever you see beamshots, please check the sky to see if they have been manipulated at all, or were taken at different times in the evening.

a couple of things.

one, as mentioned the perspectives makes comparison irrelevant since beamshots should be from the same position.

two, as znomit mentioned, the sky color seems to be waaay different in each picture. Doctored photo? auto-balance kicking in? dunno.

third, I like to see a comparison on wet roads. Any light can look brilliant and white on dry, clean asphalt. Frankly I don't give a rat's behind how blinding white a light is on a dry road. I care about how my lights work in inclement weather. A couple of car I drove with HID lights were horrific in rain season on dark, twisty roads and lots of vegetation that soak up the light. The LED lights seem to have a spectrum closer to HIDs than halogen.

I wish HIDs came in warmer colors like LEDs do. seems like if you want under 4300k, you have to go directly to smiley-face yellow 3000k.

I don't see why the change of perspective makes the comparison irrelevant. Granted it is not perfect, then what?

You can still clearly see how different the light distribution is, especially on the sides and close to the car. How smooth the beams are is also very clear.

About the color of the sky, this is exactly what you should not be looking at. At sun set the color of the sky can change dramatically in a very short period of time. Still, the un-illuminated areas of the pics are very close to pure black, so the amount of illumination from the ambiant light is minuscule compared to what we are looking at and comparing. In both cases exposure was locked as well as WB. If you think twice the sky is in fact what's irrelevant in this comparison.

tino_ale said:

I don't see why the change of perspective makes the comparison irrelevant. Granted it is not perfect, then what?

Click to expand...

I thought flashlight peopel cared about consistency in beamshots?

About the color of the sky, this is exactly what you should not be looking at. At sun set the color of the sky can change dramatically in a very short period of time.

Click to expand...

eh, not quite. he said he took the pictures 5 minutes apart. So the sky should be relatively close in color when in the pics they clearly aren't. Now what caused that color shift I wonder?

Still, the un-illuminated areas of the pics are very close to pure black, so the amount of illumination from the ambiant light is minuscule compared to what we are looking at and comparing. In both cases exposure was locked as well as WB. If you think twice the sky is in fact what's irrelevant in this comparison.

Click to expand...

we all know on CPF that beamshots can be misleading when dimmer, but bluer lights can look brighter from a photo when they aren't. I never said anything about ambient light.


Now put those two cars in raining weather and see what happens. When LEDs do as well as Halogen in wet conditions and you can buy new LED modules without selling a kidney, I'll switch.

This thread is pointless without isoscans showing the objective distribution and intensity of light. Photos are useless for anything but subjective opinions and fuelling quarrels on the internet. And if we want to talk about the "white point", we need colorimetry and SPD, too. I've driven behind a goodly number of LED headlamps -- mostly legitimate (i.e., not homemade) prototypes on closed test tracks -- and have subjectively found their light quality to be generally superior to HIDs despite the higher CCT.

However, since (1) the need for isoscans isn't likely to stop the discussion in this thread, and (2) we're unlikely to see such isoscans in the near future, I will throw my subjective assessment of the linked photos on the fire: the halogen headlamps look like they're probably reasonably well engineered. The LED headlamps appear to give wider illumination, particularly in the foreground where it's not very important to safety performance but is very critical to subjective ratings of headlamps by consumers. The photos don't provide enough information for a meaningful comparison of the headlamps' most crucial safety performance (i.e., seeing distance at particular angles).

And in that Priuschat thread, some idiot is telling a guy to get an HID "kit". Moron.

I'm sure Toyota faced some major regulatory hurdles getting an LED headlight approved for the US market-- I would expect that the lights conform to legal requirements. (But, again, we don't know with absolute certainty without those isoscans.)

Oh, I have no doubt they're compliant, and the U.S. market is actually easier than markets that require headlamps built to ECE (European) specs, which is most countries outside North America. For one thing, there's no approval involved in the U.S. market. The manufacturer self-certifies that his headlamp (and, indeed, his whole vehicle) complies with the applicable regulations. Also, the U.S. regulations themselves are easier and less expensive to meet. The low beam is less tightly controlled than ECE with respect to glare, so it's optically less challenging to make a legal U.S. low beam. And the U.S. regs don't require lens cleaners or self-levelling (though it looks as if Toyota has chosen to provide at least levelling on the LED-equipped Prius).

The question is which headlamp gives better safety performance/longer seeing distance, and that we can only determine reliably with isoscans.

(Another couple questions: How reliable and durable will these LED headlamps be…and when they fail, as some of them inevitably will, how expensive will it be to repair or replace them?)

Scheinwerfermann said:

(Another couple questions: How reliable and durable will these LED headlamps be…and when they fail, as some of them inevitably will, how expensive will it be to repair or replace them?)

Click to expand...

I'm wondering what the comprehensive coverage will cost on either the solar roof equipped Prius or the LED headlight equipped Prius (those options are, unfortunately, mutually exclusive for some arcane technical reasons) as either of those would be expensive to replace.

The Prius LED headlights are also equipped with washers, so it seems they're going all out on those babies.

people are constantly complaining about prius HID lights failing, hopefully their LEDs can do better, but only time will tell. Honestly, I think either the user is at fault for throwing d2 bulbs in a d4 application or the ballasts aren't supplying power within specs for the bulbs. Users reporting their bulbs blowing 3 times w/ aftermarket and once with OEM on ONE CAR and yet everyone at prius chat seems to think the bulbs are at fault. anyhoo.....

270winchester said:

third, I like to see a comparison on wet roads. Any light can look brilliant and white on dry, clean asphalt. Frankly I don't give a rat's behind how blinding white a light is on a dry road. I care about how my lights work in inclement weather. A couple of car I drove with HID lights were horrific in rain season on dark, twisty roads and lots of vegetation that soak up the light. The LED lights seem to have a spectrum closer to HIDs than halogen.

Click to expand...

I have halogens and they don't do jack on wet roads.

LukeA said:

I have halogens and they don't do jack on wet roads.

Click to expand...

But what kind of halogens?
Some crappy 9006/HB4 with undersized wiring, or H7+50s and custom wiring harness.

LukeA said:

I have halogens and they don't do jack on wet roads.

Click to expand...

like MichaelW said, what kind of halogen? thin gauge wiring on a 9004 with fogged up lens?

I have an ancient set of 9004 lights, but it has glass lens, and with a custom wiring kit driving a Philips VIsion Plus, it works great in wet condition.

Did I mention it's only 45w on low?

I said nothing about performance on dry roads.

I think it's interesting that when I say that halogens aren't the Light of God from the first day of creation hitting the road, I am accused of having improperly functioning headlights, which I do not.

Are you responding to a deleted post?

Because I don't see 270winchester accusing you of having improperly functioning lights.

The white point is too high with the LEDs.

Click to expand...

How can you tell given we have auto-balanced shots with different white points? (look at the sky) You'd need the original RAW files to establish this.

While we can argue to death about the best color for headlamps, what is very obvious is the LEDs lamps have more even road illumination, and by a significant margin. This cannot be manipulated by camera settings.

However, this is a function of the entire lamp assembly and not the light source. Just shows the Prius has poorly designed halogen reflectors and optics.

I think it's interesting that when I say that halogens aren't the Light of God from the first day of creation hitting the road

Click to expand...

I agree with you, but God forbid you criticize halogen for driving in inclement weather conditions because we all know know that "longer wavelengths scatter less than shorter wavelengths in rain and snow."

Plus, you need the higher CRI of halogen to better see a grey/black road at night. You know...to better define all those subtle blues and deep reds you're missing with HID :thumbsup: Ok, I'll stop.

On a wet road you ideally want your light source higher up because of the physics of refraction. Not hugging the road at 22", or whatever the absurdly low U.S. spec is. Type of light source really doesn't matter, although you won't be able to convince a lot of people in this forum.

or H7+50s and custom wiring harness.

Click to expand...

You forget to ask about fart-pipes and the size of his rear spoiler....and 55-watt halogen bulbs putting out double the light of cheaper 55-watt halogen bulbs.

Again, vertical distance from the road has the greatest bearing on the effectiveness of head lamp illumination on wet pavement, but you seriously want to talk about wiring and bulb types?

The new Prius uses projector headlights. The previous used H4/9003 dual beams.
Knowing Toyota, they are probably lifted out of the Camry-so small gauge wiring with H11s.

I'd like to see ECE projectors, with an H7, with appropriate wiring.

'The pics were taken in Manual, with ISO400, white balance set to daylight, no flash and an exposure time of 1 second. I also locked the exposure as described in the other thread.'

If the halogen lights only have half the light to work with (and use only one projector aperture), it looks like they have an appropriate distribution (but we still need the isoscans)

I'd like to see LEDs replace HIDs, but only if the CRI splits the difference between HIDs and modern halogens.
LEDs have jumped markedly in quantity [mc-e, xp-g, luminous, osram ostar], now it is time to offer 'quality'.

http://pressroom.toyota.com/pr/tms/srp-download.aspx?id=64011
http://pressroom.toyota.com/pr/tms/toyota/srp-download.aspx?id=64036

michaelw said:

Are you responding to a deleted post?

Because I don't see 270winchester accusing you of having improperly functioning lights.

Click to expand...

I think he was talking about you saying his lighting setup is mismaintained, poorly functioning, and incapable of providing the correct amount of power to the stock (and therefore, crappy) bulbs.

MichaelW said:

The new Prius uses LED projector headlights. The previous used H4/9003 dual beams.you mean reflector HIDs
Knowing Toyota, they are probably lifted out of the Camry-so small gauge wiring with H11s.Not gonna say anything about the std option, but the LED option is definitely not an H11 projector. It had to be engineered specifically for headlight function.

I'd like to see ECE projectors, with an H7, with appropriate wiring. toyota has efficiency and green-ness in mind with the prius. Seems like they ought to use HID or LED.

'The pics were taken in Manual, with ISO400, white balance set to daylight, no flash and an exposure time of 1 second. I also locked the exposure as described in the other thread.'

If the halogen lights only have half the light to work with (and use only one projector aperture), it looks like they have an appropriate distribution (but we still need the isoscans)

I'd like to see LEDs replace HIDs, but only if the CRI splits the difference between HIDs and modern halogens. would be nice to get higher cri HID than what is currently offered. Sure, black road, white lines, but the creatures and peoples on the side of the road are usually not so obvious. Higher CRIwould help in this regard.
LEDs have jumped markedly in quantity [mc-e, xp-g, luminous, osram ostar], now it is time to offer 'quality'.

http://pressroom.toyota.com/pr/tms/srp-download.aspx?id=64011
http://pressroom.toyota.com/pr/tms/toyota/srp-download.aspx?id=64036

Click to expand...

Blasterman, I agree with the angle of light being most important in wet conditions, but I still don't know where to stand on the "longer wavelengths scatter less than shorter wavelengths in rain and snow" bit. it just doesn't seem likely to affect vision in this particular circumstance. It might perhaps explain any sort of halo-ing that may occur in fog, but whatever it does, I'm of the opinion that no matter what science or people on the internet say, if yellow helps in fog, yellow I will use!