[f450]

I was having this discussion in another topic and felt it could warrant its own thread.

With xenon (or are they Bi-xenon?) lights becoming increasingly common on our roads, it made me think about how dangerous this actually is in India. Agreed it's safe for the driver of the car which has these lights, but what about oncoming traffic? I, for one, am effectively blinded when there's car on the opposite side coming with high beam xenon's. Naturally, I'm going to temporarily not see things in front of me.

With Skoda offering them as standard with the Laura, there are more xenon's than ever before. They're affordable to most people. And added to that, youngsters who modify their cars seem to put them on as they look cooler...

I can understand that these lights can be useful on the highway, but in the city, they do more harm than good.

[ImmortalZ]

Xenons on projectors are fine. Xenons on reflectors designed for halogens will blind you.

Only bi-xenons will do high beam. But even low beam xenons in a reflector will blind you with horrendous glare.

HIDs have been standard issue on C segment cars in the west for years now. As we know, they have stricter rules (which are enforced too) and if they made driving dangerous, they wouldn't have been allowed in the first place.

If you wish to really know the difference, go find a Laura at night, ask the owner nicely to turn the headlight on. Look at it and see how it throws its light. Now go find a boy racer with 6000k in his reflectors. Try and keep your eyes open while facing it for 2 seconds. You'll see what I mean.

The difference is that projectors have plates inside them which give a sharp cut off. I've attached a few pics which explain what I mean (RHD, so the beam shape is inversed). In bi-xenons, this plate is attached to a solenoid which, when actuated by the hi-beam setting on the headlight stalk, moves the plate letting the full beam out of the projector. Projectors also... project their light in a very defined and focused shape onto the road instead of reflecting them and scattering them all over the place, as reflectors do. Also remember that halogen lamps are inherently much less efficient in their operation. Only a very little percentage of the power consumed gets turned into light. I believe it is as low as 15% in halogen lamps (one of the more efficient filament based lamps). In the case of HID, this figure is much higher. The usable light from them therefore is also much higher.

Put that brighter bulb in a reflector which is designed to focus a differently shaped light source - a filament of considerable length compared to a point light source of a HID bulb - at a different focus point and things go south very quickly. Do keep in mind that there are HID bulbs designed for reflectors, when put in a specifically designed reflector, will provide reduced glare. However, they will don't offer nearly as much lighting efficiency as a projector and the shimmering glare effect will remain to some extent. This is why such lights are so rare. There is an issue of cost here as well. Projectors aren't cheap. The ones on a Honda S2000 (arguable the best low beam on the planet) go for 800$ a pair, second hand. And that's just the projector. Bi-xenons of good quality are similarly expensive as well.

[CBlazer]

Originally Posted by f450

I, for one, am effectively blinded when there's car on the opposite side coming with high beam xenon's. Naturally, I'm going to temporarily not see things in front of me.

I have found that Xenons fitted after market are the ones that are too bright and blinding for on coming traffic. I find even bikes fitted with some lousy bright bluish lights whose main purpose seem to be irritating other drivers.

I have rarely had a problem with headlights of Laura or other cars with factory fitted Xenons. (I guess ImmortalZ post above explains why.)

[f450]

Originally Posted by ImmortalZ

Xenons on projectors are fine. Xenons on reflectors designed for halogens will blind you.

Only bi-xenons will do high beam. But even low beam xenons in a reflector will blind you with horrendous glare.

HIDs have been standard issue on C segment cars in the west for years now.
If you wish to really know the difference, go find a Laura at night, ask the owner nicely to turn the headlight on. Look at it and see how it throws its light. Now go find a boy racer with 6000k in his reflectors. Try and keep your eyes open while facing it for 2 seconds. You'll see what I mean.

I didn't understand a lot of that, but I think I got "xenons are ok, reflectors are not". I'm not very sure about terms, but to ,me, "white lights" in general are bad. These days, I see Swifts, Vernas etc. that are at very high speeds and are blinding you at the same time. I almost hit the divider!

You mentioned the West. I think it's a lot safer for these lights in the West because they have a strict lane system there, and also they very rarely are on the opposite side of the road (while overtaking, which is very common in India). Also add to that the fact that everyone is more or less going at the same speed, so there are less chances of ramming into the person in front of you. There are no people running across the road, no dogs, cows, open manholes....you get my drift.

[R2D2]

Originally Posted by ImmortalZ

Xenons on projectors are fine. Xenons on reflectors designed for halogens will blind you.

Only bi-xenons will do high beam. But even low beam xenons in a reflector will blind you with horrendous glare.

HIDs have been standard issue on C segment cars in the west for years now. As we know, they have stricter rules (which are enforced too) and if they made driving dangerous, they wouldn't have been allowed in the first place.

If you wish to really know the difference, go find a Laura at night, ask the owner nicely to turn the headlight on. Look at it and see how it throws its light. Now go find a boy racer with 6000k in his reflectors. Try and keep your eyes open while facing it for 2 seconds. You'll see what I mean.

The difference is that projectors have plates inside them which give a sharp cut off. I've attached a few pics which explain what I mean (RHD, so the beam shape is inversed). In bi-xenons, this plate is attached to a solenoid which, when actuated by the hi-beam setting on the headlight stalk, moves the plate letting the full beam out of the projector.

Put the same bulb in a reflector which is designed to focus a differently shaped light source - a filament of considerable length compared to a point light source of a HID bulb - at a different focus point and things go south very quickly. Do keep in mind that there are HID bulbs designed for reflectors, when put in a specifically designed reflector, will provide reduced glare. However, they will don't offer nearly as much lighting efficiency as a projector and the shimmering glare effect will remain to some extent. This is why such lights are so rare. There is an issue of cost here as well. Projectors aren't cheap. The ones on a Honda S2000 (arguable the best low beam on the planet) go for 800$ a pair. And that's just the projector. Bi-xenons of good quality are similarly expensive as well.

You get 2 types of HID bulbs...the D2S and D2R. The D2S are designed for cars with projector headlamps and the D2R for cars with reflectors. The 'R' denotes reflector and are supposedly more environmentally friendly (low mercury). D2Rs have a special mask on the bulb that prevents glare and maintains the cut off (light/dark boundary).

If you're fitting aftermarket HIDs most cars would take D2Rs. Not sure if they are available though. The Corolla Altis comes with D2R bulbs.

Either way, a blue bulb (pseudo HID) or an out of focus D2S are deadly to oncoming traffic. I wish people would have some sense. A blinded driver with his car in the opposite lane is deadly.

Rgds,

[kbk_75]

Factory fitted xenon lights are infinitely better than reflectors because the cars that come with xenons as OE have a levelling mechanism where the lights will automatically shoot lower when going uphill or with a heavy load in the back of the car and vice versa. As ImmortalZ explained they also have a clearly defined area that they light which PREVENTS blinding oncoming traffic even on high beam.

After market HIDs are the problem.

[R2D2]

Originally Posted by kbk_75

Factory fitted xenon lights are infinitely better than reflectors because the cars that come with xenons as OE have a levelling mechanism where the lights will automatically shoot lower when going uphill or with a heavy load in the back of the car and vice versa. As ImmortalZ explained they also have a clearly defined area that they light which PREVENTS blinding oncoming traffic even on high beam.

After market HIDs are the problem.

Cars with factory fitted HIDs in reflector housings also have automatic headlamp levellers. The Corolla Altis is among them.

Rgds,

[androdev]

i can tell you that factory fitted xenons that are not messed with are as safe if not safer than conventional halogens. factory fitted xenons
1. have cut-off like Immortalz explained (if you stand in front of the car, the beam doesn't go above your knee level)
2. right-side xenon will focus lower than left-side one (to see road-signs, and not to blind on-coming traffic)
3. have self-levling motors to lower the beam if the car is heavily loaded on the backside so that the beam doesn't point higher
4. have washers to clean the light housing glass so the light doesnt diffuse and glare due to mud/dust.

*But* even OE xenons can point higher if the factory settings are messed up and they can be a real pain. The after market blinders are another story (very popular among swift, civic and accord).

[ImmortalZ]

Originally Posted by f450

I didn't understand a lot of that, but I think I got "xenons are ok, reflectors are not". I'm not very sure about terms, but to ,me, "white lights" in general are bad. These days, I see Swifts, Vernas etc. that are at very high speeds and are blinding you at the same time. I almost hit the divider!

You mentioned the West. I think it's a lot safer for these lights in the West because they have a strict lane system there, and also they very rarely are on the opposite side of the road (while overtaking, which is very common in India). Also add to that the fact that everyone is more or less going at the same speed, so there are less chances of ramming into the person in front of you. There are no people running across the road, no dogs, cows, open manholes....you get my drift.

You misunderstood my post.

In a nutshell, I meant, xenons in projectors good, xenons in reflectors bad. However, "xenons" is not the right terminology here. Do remember you can get xenon filled filament lamps. The proper name for these bulbs are HID - high intensity discharge.

Yes, the 130/100 bulbs that people put in their headlamps also blind people. HIDs in reflectors however, are in a wholly different league when it comes to blinding people.

Originally Posted by R2D2

You get 2 types of HID bulbs...the D2S and D2R. The D2S are designed for cars with projector headlamps and the D2R for cars with reflectors. The 'R' denotes reflector and are supposedly more environmentally friendly (low mercury). D2Rs have a special mask on the bulb that prevents glare and maintains the cut off (light/dark boundary).

If you're fitting aftermarket HIDs most cars would take D2Rs. Not sure if they are available though. The Corolla Altis comes with D2R bulbs.

Either way, a blue bulb (pseudo HID) or an out of focus D2S are deadly to oncoming traffic. I wish people would have some sense. A blinded driver with his car in the opposite lane is deadly.

Rgds,

I'd like to add that just by using a D2R bulb, you will not fix the problem. It prevents the HID from flat out blinding someone coming your way. But it will not get rid of the extremely harsh glare around the headlight (the star light structures you see). You still need a specially designed reflector with a D2R bulb because of the different light source shape and focus differences to have a somewhat sane result.

[R2D2]

Originally Posted by ImmortalZ

I'd like to add that just by using a D2R bulb, you will not fix the problem. It prevents the HID from flat out blinding someone coming your way. But it will not get rid of the extremely harsh glare around the headlight (the star light structures you see). You still need a specially designed reflector with a D2R bulb because of the different light source shape and focus differences to have a somewhat sane result.

Oh not really. Take a look at the TCA with the low beams on..no stray light. It is as if there was a projector there.

There is no visibile difference in the reflector of the TCA with the HIDs and the one without (with 9006/HB4 low beam halogens bulbs). So it should be the D2R bulb that takes care of the boundary combined with the auto headlamp levelling system.

Cheers!

[f450]

Originally Posted by ImmortalZ

You misunderstood my post.

I had no idea there were so many different types!

I just call them all "white lights".

In fact, I guess a lot of people do

[srishiva]

I remember that there was some rule in the U.S (maybe among manufacturers) to not fit HIDs on high beams initially. Don't know what happened to that.

[ImmortalZ]

Originally Posted by R2D2

Oh not really. Take a look at the TCA with the low beams on..no stray light. It is as if there was a projector there.

There is no visibile difference in the reflector of the TCA with the HIDs and the one without (with 9006/HB4 low beam halogens bulbs). So it should be the D2R bulb that takes care of the boundary combined with the auto headlamp levelling system.

Cheers!

To be honest, I've never seen a TCA with HIDs in person. Most of my information comes from someone who works in manufacturing projectors. We both play the same obscure online multiplayer game. Weird place to meet I know.

[R2D2]

Originally Posted by ImmortalZ

To be honest, I've never seen a TCA with HIDs in person. Most of my information comes from someone who works in manufacturing projectors. We both play the same obscure online multiplayer game. Weird place to meet I know.

I think you should see it for yourself. Nice piece of work actually. When I drive at night I really cant believe I have a set of HIDs with reflectors. The low beam is beautiful, crisp and detailed. I wonder how I did without HIDs. Seriously, HIDs spoil you.

I'd have preferred Toyota kitting the TCA with projectors. The HIDs bulbs are fitted on the high trim models so a few thousands extra wouldnt have mattered. They are probably leaving it for a mid life upgrade. That is when I expect them to intro the 2ZR-FE engine, the one thats doing the rounds in the US.

Regards,

[f450]

The S-class and 7-series have this option in which the headlights have adaptive adjustment, so if u turn left (right), the lights turn left(right). I'm not sure how they work with height though...