What is the advantage of HID over halogen?

Thank you.

HID will blind the drivers in on-coming traffic quicker.

That is why it’s crucial to have the headlamps properly aimed

Don’t consider an HID conversion, lots of cheap/poor ones out there. As for original equipment, I guess some HIDs might be better, but the replacement costs are HUGE (even if rare). I prefer halogens.

HIDs, from what I hear, allow one to see the sides os the road better. Frankly, when one of my halogen bulbs burns out, I like being able to buy a replacement for 10 buck at Wal-Mart and have it fixed before I leave Wal-Mart parking lot. I think HIDs are quite an expense and hassle to replace.

A disadvantage of HID’s is very expensive to replace, and some cars experience vandalism as HID’s have some value on the “black market”. Supposedly HID give off more light, but I’m not convinced the greater illumination is worth the costs and risks of theft.

If you have a vehicle and want more powerful lights consider aftermarket “fog lights” and driving lights that are available at most auto supply stores.

With factory HIDs you can actually see deer on the side of the road in time to avoid them. Halogen are just upgraded standard headlights. They help but not that much.

I agree that aftermarket HID setups aren’t worth it. In fact, most will just be blue tinted halogen bulbs. Those bulbs aren’t worth the packaging they come in. I had some of the super bright blue bulbs once and couldn’t see much of anything; the blue lighting dispersed too easily. In rain at night, I might as well have been using just my parking lights to illuminate the road. I switched back to halogen bulbs for the Civic.
With properly aimed factory HIDs, you can’t really tell much difference with oncoming traffic.
I’d like to try a Cx-7 that has the factory halogen setup, just to see the difference in lighting. But, my factory HIDs haven’t caused anyone to flash their brights at me, thinking I’d left mine on, and they illuminate the road just fine. The brights are halogen bulbs that come on and work WITH the HIDs

Halogens are just incandescent bulbs filled with a halogen gas under pressure. The presence of the halogen helps keep tungsten from ‘evaporating’ from the filament and bonding to the glass, which dims a lamp over time in the same fashion your vision gets dim if you have cataracts.

en.wikipedia.org/wiki/Halogen_lamp

There are many types of HID lamps. The ones used in cars tend to have a whiter, more consistent light that illuminates the entire road better. They are also more efficient and use less energy.

en.wikipedia.org/wiki/High-intensity_discharge_lamp

I will say one thing–once you have a car with HID lamps, you will never want to go back to ordinary headlights. Getting a little older, my night vision isn’t what it once was. It’s a pleasure to drive at night again with HID lamps. I hope to never have to settle for a car without them again. I don’t think they’re any more blinding than any other headlight. Possibly less so, as the light seems to be diffused better over the area in front of the car.

This past spring we traded an expensive car that had HID headlights for a newer car with halogen headlights. I saw no advantage to the HID headlights when we had them and don’t regret that they are gone.

I’m very pleased with the HID’s on my TL. They’re a lot brighter and have longer throw than the halogens on the SO’s (newer) car. But the car came from the factory with them. With few exceptions, aftermarket HID conversions are crap.

As for replacement costs, it’s a lot cheaper to order them online than get them at the dealership. I looked it up when I got the car, and I can replace both for around $200. And since they last a very long time, especially compared to regular bulbs, it’ll probably work out to be about the same, cost-wise.

One trick with HID’s - do not flash them at drivers, and don’t enable the automatic headlights. Blinking on and off over a short period of time shortens their life significantly. If you turn them on, leave them on.

Of course, HID’s are already on borrowed time - LED lights are cheaper, longer lasting, and just as good. And BMW has a funky new laser light system that’s supposed to be absolutely fantastic (but unfortunately you have to deal with the problems that the rest of the car will cause in order to use them :wink: )

LED lights are cheaper, longer lasting, and just as good.

I’m slowly switching the bulbs in my house over to LED’s. The cost has come down significantly in the past 5 years. And I get coupons all the time and look for sales. Just last week I bought 4-60 watt bulbs for less then $20/each (after coupon and mail in discount).

Of course, HID’s are already on borrowed time - LED lights are cheaper

My under-cabinet lights were 2x more expensive than halogens but they advertise ~50x the life. More expensive to buy but supposedly cheaper in total cost of ownership. LED headlamps for autos are still relegated to the high end market and are uber-expensive. Have you found different? Any examples?

longer lasting
Speaking of headlamps specifically, the halogens are typically around 1000 hrs, Xenon HIDs can go 2000 hrs and I haven’t seen any data on LED lifetime in these high powered applications. Where I work, we build some fairly high power LED systems and the lifespan is rated around 5000 hours with adequate heat dissipation. Surprisingly, the output drops off fairly consistent with lamps that experience solarization from electrode or filament sputter/wear.

, and just as good.
HIDs have roughly 2x the broadband light output compared to tungsten halogen lamps. LEDs are going to be much more peaky and so how they are specified will make a big diference in comparing apples-apples. By and large, the spectral output will not be as broad even with multiple emission wavelengths (dies) and phospher conversions. What looks good on paper is often very subjective to the user. I haven’t seen an LED headlamp yet, is your experience that they are better for illumination? (intensity, uniformity, color rendering…)

Where I work, we build some fairly high power LED systems and the lifespan is rated around 5000 hours with adequate heat dissipation.

What heat?? Didn’t think LED’s produce that much heat if any. I have 100 watt outdoor LED light that I can touch when it’s on. It’s not even warm.

My under-cabinet lights were 2x more expensive than halogens but they advertise ~50x the life.

I meant that LED lights are cheaper than HID lights, not halogen.

LED headlamps for autos are still relegated to the high end market and are uber-expensive.

Things that are uber expensive to the consumer aren’t always expensive to the manufacturer. I remember back in the days when math coprocessors were a big deal in computing, the 486 processor was available with or without one. If you got it with a math-co, you paid a lot more. The dirty secret was that ALL 486’s had the math-co onboard, and it was just disabled for the cheaper chips.

Speaking of headlamps specifically, the halogens are typically around 1000 hrs, Xenon HIDs can go 2000 hrs and I haven’t seen any data on LED lifetime in these high powered applications.

I’m still running the original HID bulbs in my TL. It’s not unusual for people to go 100k+ miles before they need replacement. Plus keep in mind that 1000 extra hours in a headlight is significant, because it’s not like you’ve got them on every time you’re in the car. That can translate to years in some cases.

LED’s are usually rated between 50,000 and 100,000 hours, but that’s for stationary installs - no one’s really talking about automotive applications. You can extrapolate, though, given that stationary HID installs are usually rated around 30,000 hours

I haven’t seen an LED headlamp yet, is your experience that they are better for illumination? (intensity, uniformity, color rendering…)

I can’t speak for the automotive side specifically because I don’t have an LED-equipped car. But I’m a photographer by trade, and I can say that you will pry my LED lighting equipment out of my cold dead hands. :wink: And we’re not talking studio applications here - I’m out in all weather/temperatures/conditions. They use significantly less energy, and with the lights I use (which won’t be necessary in cars) I can replicate the entire color spectrum from black to pure white - this tells me that they’ll be able to tune LED headlamps to emit whatever color they want. As for brightness, watt for watt my LEDs are vastly brighter than my old tungsten ones. My backup camera’s toplight used to be a 50 watt battery draining beast. I’ve replaced it with a 23 watt LED that puts out just as much light. The difference is even more noticeable when you look at the big stand lights.

@MikeInNH: LEDs don’t generate as much heat as incandescent or other technologies, but they do have to dissipate heat to keep from burning up, like any semiconductor device with an appreciable amount of power running through it. LED lamps that have many small LEDs don’t run as hot as those that have either one or a handful of high-power LEDs. If you look at an LED lamp that has a high output and only one or a few lamps, you will typically see a large heat sink attached to the LED.

Yep, lots of them have cooling fins of various configuration:

What heat?? Didn’t think LED’s produce that much heat if any. I have 100 watt outdoor LED light that I can touch when it’s on. It’s not even warm

It’s all relative. The LED die is tiny. The heat is produced closer to the backside of the die, not out the front. The local heat at the die is significant relative to its size and must be removed efficiently to avoid burning up the die. We use metal core PCBs (aluminum inner layers) to conduct the heat away from the dies. There is a ton of IP in heat management (especially if you want to have stable spectral output across the full temperature range) for LED designs. We make arrays of just about any size you could envision from several dies to a 1000 in a single array. Every single one of these needs to be designed with heat dissipation in mind. Some of the higher power LEDs would burn your eyes out if you were foolish enough to look directly at them without protection. Even something like a 10 element array will be quite warm to the touch if you could access the PCB they are mounted onto without the secondary heatsink attached. A dinky 100W illuminator has already spread out the heat to a virtually unnoticeable (to your finger) increase above ambient by the time it reaches the outside surface of the assembly.

@shadowfax-

My under-cabinet lights were 2x more expensive than halogens but they advertise ~50x the life.

I meant that LED lights are cheaper than HID lights, not halogen.

Where do you find high power LEDs that compete head to head with HIDs in performance that are cheaper to buy? we do both technologies and I can tell you LEDs are always more expensive than the established, conventional lighting technologies. Are you referring to photoflash? That might be one application since the ballast/power supply integration in the smaller space leads to cost issues.

LED headlamps for autos are still relegated to the high end market and are uber-expensive.

Things that are uber expensive to the consumer aren’t always expensive to the manufacturer. I remember back in the days when math coprocessors were a big deal in computing, the 486 processor was available with or without one. If you got it with a math-co, you paid a lot more. The dirty secret was that ALL 486’s had the math-co onboard, and it was just disabled for the cheaper chips.

I agree when the result is a byproduct of the manufacturing process. Look at your wiring harness, it has all the connectors for every option whether you have them or not. It’s cheaper that way. Same for the circuit boards. Sometimes they are populated and disabled, sometimes just not populated. But this is different. It’s a wholly different design approach with costs specific to different technology. They call it the bleeding edge for a reason for those early adopters…

Speaking of headlamps specifically, the halogens are typically around 1000 hrs, Xenon HIDs can go 2000 hrs and I haven’t seen any data on LED lifetime in these high powered applications.

I’m still running the original HID bulbs in my TL. It’s not unusual for people to go 100k+ miles before they need replacement. Plus keep in mind that 1000 extra hours in a headlight is significant, because it’s not like you’ve got them on every time you’re in the car. That can translate to years in some cases.

Yep, no argument there, just comparing apples to apples not absolute lifetime in application.

LED’s are usually rated between 50,000 and 100,000 hours, but that’s for stationary installs - no one’s really talking about automotive applications. You can extrapolate, though, given that stationary HID installs are usually rated around 30,000 hours

Here’s a dirty little secret, the 50k hours specification is under best case conditions. That does not include driving the dies at maximum specified power or exposing them to other application specific conditions that are detrimental to life.

No way a Xenon HID lamp will last 30k hours. By some miracle if it’s still lit at that age, it will be 80-90% down in intensity and useless as an illuminator. CW Xenon used in illumination applications (projectors, surgical fiber optic illuminators for example) are 50% down after 1500 hours and tossed when they reach 2000 hours as unusable. They are still lit but so far degraded they cannot perform their function anymore.

I haven’t seen an LED headlamp yet, is your experience that they are better for illumination? (intensity, uniformity, color rendering…)

I can’t speak for the automotive side specifically because I don’t have an LED-equipped car. But I’m a photographer by trade, and I can say that you will pry my LED lighting equipment out of my cold dead hands. :wink: And we’re not talking studio applications here - I’m out in all weather/temperatures/conditions. They use significantly less energy, and with the lights I use (which won’t be necessary in cars) I can replicate the entire color spectrum from black to pure white - this tells me that they’ll be able to tune LED headlamps to emit whatever color they want.

You can’t “tune” an LED to produce any spectrum of light. It’s a function of the materials used to construct the device and the phosphors. They typically have a very narrow emisson band of around 10nm or so. The white light you percieve with your eye is accomplished by mixing a number of discrete wavelengths and using phosphors to extend the emission bands enough to be good for the human eye (and your camera detector). The lack of emission in quite a few wavelengths in the visible region is limiting LEDs in many applications currently. The holy grail has been interior lighting up until recently and that’s all anybody has been working on. It’s a HUGE market and getting the right combination of emitters and phosphors to produce acceptable light has been a long road. For analytical applications that use light in absorption spectroscopy for example, the Xenon HID is still untouchable by LEDs due to the broader, fuller spectrum of light produced.

As for brightness, watt for watt my LEDs are vastly brighter than my old tungsten ones. My backup camera’s toplight used to be a 50 watt battery draining beast. I’ve replaced it with a 23 watt LED that puts out just as much light. The difference is even more noticeable when you look at the big stand lights.

Yes, this is where they “shine” (pun intended) and are a huge improvement over the prior technology. There are still hand-held camera manufacturers using grain of rice sized xenon flash lamps for certain color rendering enhancements but with the improvements in LEDs, they are dwindling every day…

@TwinTurbo

Where do you find high power LEDs that compete head to head with HIDs in performance that are cheaper to buy?

Have you seen how much an OEM HID assembly is? If I get just the HID replacement bulbs from my dealership I’m in it for a grand. If I replace the whole assembly, it’s even more than that.

You can't "tune" an LED to produce any spectrum of light.

Not an individual diode, no, but if you have an array of differently colored LED’s, you can cause a color shift in overall output. Here’s one of the lights I use which lets me go from 2700K to 10,000K: http://www.bhphotovideo.com/c/product/812828-REG/Arri_553500C_L7_C_Color_LED_Fresnel.html