Advocacy & Safety - if you have a really powerful front light on your bike..

do you have to dip it when cars come?

:D

define really powerful.

No way it's powerful enough to warrant that. Aren't car headlights 50W when dimmed?

With all this blinding xenon lamps rolling on the street, are you kidding?

I had to be careful with a helmet-mounted 15W halogen light. I don't bother with that anymore.

My bar-mounted halogen is aimed low enough that it isn't a problem.

that day is here for some people. I've been riding in a group at night and opposing drivers turned on their brights. OTOH, many drivers are idiots, and some apparently turn on their brights when they don't understand what they are seeing. They get the full helmet light in the face treatment.

No way it's powerful enough to warrant that. Aren't car headlights 50W when dimmed?

Yes, but it's 50 watts with a full cutoff below eye level. If you have ever had a car with misaligned lights coming towards you, you will know that even low beams can be blinding. This is my biggest gripe about bike lights - they almost all have a circular beam instead of a proper shaped beam with cutoff. 10 watts can be irritating, 30 watts can be blinding, if aimed wrong. 1000 watts can be fine, if aimed right.

Mainly what car lights do when going to low beams is not to dim but to move the beam so that they are not shining up and into other drivers' eyes.

My niterider classic has a switch right at my right hand... I have dimmed it in certain conditions... but only after I was sure I was seen first. I have 32 watts of light when it is all lit up.

I have been told I look like a motorcycle on approach. Good enough for me.

With all this blinding xenon lamps rolling on the street, are you kidding?

Yeah, I hate those things. And half the drivers seem to be driving with their high beams on too.

The trouble is, it seems people think safety only involves themselves and no one else. As long as they can see better, it's safer. Doesn't matter that they're blinding everyone else.

They can see better, so those lights are safer.

dip it in deference to the motorists? naw.

high powered LEDs should be getting shaped beams, some of the Lumotec dynamo lights are shaped, the Light in Motion SECA 400 and 700s have shaped beams.

I suspect niterider may do the same with 2011s uberlights.

the new LED lights are getting so hella powerful there has to be a top illumination limit reached in the next 5 years, lights are now the brightness of a car headlamp.

I feel my safety is imperative on the roads so i do not aim my light down but level to help me ride and to better catch motorists attention. it spills down to the road enough for me to see the close stuff.

do you have to dip it when cars come?

:D

Having a friend ride towards you while you are sitting at car seat level would provide a good answer to your question.

Bike headlights can definately be too bright, and cause temporary blindness in an oncomming driver's (or cyclist's) eyes. Car headlights are large extended sources. Bike headlights, especially HID and LED, are very small sources. When both are imaged onto the retina, the small source creates waaay higher light energy density on the retina making a localized blind spot much more likely.

Also, car headlights spread their light out over a much wider area than bike headlights, and cut it off below intended eye level for the safety of oncomming drivers. Bike headlights don't do that. Bike lights on a helmet are the worst thing to do, for on the road. Everything you look toward gets the full beam right in the eyes. Do YOU want a temporarily blinded driver comming around the corner behind YOU?

Has anyone heard of a cyclist getting hit because he/she blinded a motorist with a powerful headlight?

Has anyone heard of a cyclist getting hit because he/she blinded a motorist with a powerful headlight?

How do you know it wasn't a she?

Motorists often say "I didn't see them" after a collision with a cyclist. Cyclists take that to mean that they need to make themselves more visible by using fluorescent clothing and more and more light. And strobing headlights. I don't believe it. Motorists say that because:
a) they're lieing, and that's the easy thing to say immediately,
b) they saw them but it didn't compute in their head because they were distracted,
c) they saw them but didn't react fast enough, so revert to (a) to cover it up,
d) they didn't see them because the cyclist was in a weird and unexpected place like the left side sidewalk or passing on the right at a corner, or
e) they were temporarily blinded by the sun (or some other combination of lights) in their eyes.

None of the situations above require more light from the cyclist to prevent the collision. Guilty motorists lie. Cyclists don't need to use a barge light because motorists lie about their ability to see cyclists after hitting them.

Motorists often say "I didn't see them" after a collision with a cyclist. Cyclists take that to mean that they need to make themselves more visible by using fluorescent clothing and more and more light. And strobing headlights. I don't believe it. Motorists say that because:
a) they're lieing, and that's the easy thing to say immediately,
b) they saw them but it didn't compute in their head because they were distracted,
c) they saw them but didn't react fast enough, so revert to (a) to cover it up,
d) they didn't see them because the cyclist was in a weird and unexpected place like the left side sidewalk or passing on the right at a corner, or
e) they were temporarily blinded by the sun (or some other combination of lights) in their eyes.

None of the situations above require more light from the cyclist to prevent the collision. Guilty motorists lie. Cyclists don't need to use a barge light because motorists lie about their ability to see cyclists after hitting them.


Using a barge light helps to prove the lie. :D "what you couldn't see that bright flashing UFO right in front of you..." You shouldn't be driving if that is the case.

After installing my HID light, it reduced the number of side pull outs and left hooks dramatically, and it's a great light, but I've made a few peds grumble about being blinded by it. I've even had several motorists, possibly cyclists themselves, stop and comment positively on how bright my light was when I first installed it, but I'm sure there have been other motorists who may not think so highly of it.
I'm very consciences of how I have the light aimed, but with one setting, it's difficult to have good distance coverage for the speeds I ride at, and not partially blind someone in the process.

Motorists often say "I didn't see them" after a collision with a cyclist...

not the motorists that have hit me.

For the times I was able to ask if they saw me (because I couldn't believe that they didn't), each one said they did.

When asked why they still moved into my path, they became slack-jawed. No answer.

I can only guess, they saw me and I didn't register as a threat so they drove right into me.

Considering how much room many drivers leave in front of them when they stop, and how sharply they cut right corners, I presume most have no idea where the outer surfaces of their vehicles are in relation to their bodies. That's the real danger in my opinion.

Also, drivers who've never ridden a bike (most) have no idea how fast bikes typically go, much less judge the time of convergence when they see them a block away. They see them, look the other way slowly, pull out thinking the kid on the bike is down the block and WHAM!!!

Both things are worse at night. More light doesn't help either. Best you can do is use lots of light pointed at the ground. There will be plenty of spill light for cars to see you, BUT you must ride expecting each one of them to pull out stupidly and kill you. If you want to add light for your own safety, I recommend low mounted lights that cast more obvious shadows on the road surface. Hitting a stick can kill you just as dead as a car can. Helmet mounted lights remove shadows from what they illuminate. Not good.

Yes, but it's 50 watts with a full cutoff below eye level. If you have ever had a car with misaligned lights coming towards you, you will know that even low beams can be blinding. This is my biggest gripe about bike lights - they almost all have a circular beam instead of a proper shaped beam with cutoff. 10 watts can be irritating, 30 watts can be blinding, if aimed wrong. 1000 watts can be fine, if aimed right.

Mainly what car lights do when going to low beams is not to dim but to move the beam so that they are not shining up and into other drivers' eyes.

Also it's 50 watts of incandescent. A 5 watt LED is going to be putting out a similar amount of light.

And it's spread out. A typical high power bike light has a deep reflector to make for powerful throw and a fairly narrow beam.

I try to use my weaker light if I'm just riding on the roads. It's got a much wider beam and it's not so obnoxiously bright. I don't need it to see, I just need it to be seen.

Now, on the bike paths (especially in the winter), I want the bright light with the narrow beam. I need to see what's coming, and there's nobody else out to see me anyway ;).

Using a barge light helps to prove the lie. :D "what you couldn't see that bright flashing UFO right in front of you..." You shouldn't be driving if that is the case.

No it doesn't. And it doesn't precisely because:
1. The news media will not report what kind of light you used.
2. If they did, we're entirely incapable of communicating how bright a light is without showing it, live or on video.

The only way that helps is for the people who see you, at night, in person and think "that guy bikes with a _really_ bright light." For everyone else, a bike light is a mystery.

My niterider classic has a switch right at my right hand... I have dimmed it in certain conditions... but only after I was sure I was seen first. I have 32 watts of light when it is all lit up.

I have been told I look like a motorcycle on approach. Good enough for me.

What does that involve as far as batteries go?

do you have to dip it when cars come?

:D

Nope, but if a car is approaching me from the opposite direction with headlights that are brighter then mine I'll use my hand to cover and uncover the lights to let them know that they still have their highbeams on.

What does that involve as far as batteries go?

You can see my whole set up on this lighting thread.

http://www.bikeforums.net/showpost.php?p=9909551&postcount=166

The big white bottle battery is my 4500maH 12v NiMH battery. Lasts for about 3 hours with everything on high.

Looks just like this:
http://www.batteryspace.com/waterbottlenimhbattery12v4500mah50wwithtrail-techfemaleplug.aspx

Except mine is a bit older and has a more generic connector which I spliced into the old NR connector.

I would like to see my light from a car, but it's dyno powered and I don't really trust anyone to ride my bike. I have had a couple of drivers wait for me for a very long time. That indicates that it's bright enough to confuse them about the source.

Car lights are nearly blinding, even on low. On bright, the effect is extended, and the after-effects are worse. I am approximately half as bright as a car at speed. I'm sure it's at least a little blinding, and that's exacerbated by the spread of the lights. I do have the most tightly focused lens I could find.

The big white bottle battery is my 4500maH 12v NiMH battery. Lasts for about 3 hours with everything on high.
4500 mA-hr @ 12 V is only 54 W-hrs. So if your lights are using 32 W then they should run for about 1.7 hrs. Either your battery is putting out much more than its rated capacity or 32 W lights are going to be getting very dim long before 3 hours.

Maybe not for cars but please dip it when you're passing oncoming bike traffic. It feels like once a week I pass somebody pointing some strobing monstrosity right into my eyes. Disorients the hell out of me.

do you have to dip it when cars come?

:D

No, you need it to be properly adjusted, which is a problem with handlebar mounted lights, they often are not fixed securely in place and aimed properly, if you can't sufficiently tighten it, take a strip of old inner tube, cut a piece that will fit under the bracket, but about 3 times as wide, fold it over a couple of times and fit it under the bracket, so that it doesn't move when riding. A high up light needs to be aimed slightly down, in a completely dark place it should show about 4-5m down the road. As for poorly aimed lights, most cars are not adjusted properly either...

Motorists often say "I didn't see them" after a collision with a cyclist. Cyclists take that to mean that they need to make themselves more visible by using fluorescent clothing and more and more light. And strobing headlights. I don't believe it. Motorists say that because:
a) they're lieing, and that's the easy thing to say immediately,
b) they saw them but it didn't compute in their head because they were distracted,
c) they saw them but didn't react fast enough, so revert to (a) to cover it up,
d) they didn't see them because the cyclist was in a weird and unexpected place like the left side sidewalk or passing on the right at a corner, or
e) they were temporarily blinded by the sun (or some other combination of lights) in their eyes.

None of the situations above require more light from the cyclist to prevent the collision. Guilty motorists lie. Cyclists don't need to use a barge light because motorists lie about their ability to see cyclists after hitting them.

It's called situational blindness and, yes, it is a real phenomena. I've experienced it from both sides. The guy that hit me while I was riding really, really didn't see me. He was as shocked as I was as I slide across his hood. The pedestrian I hit with my car I didn't see at all until she was standing in front of my car. People in cars can miss trains (I had a great uncle killed that way), a bicycle is pretty easy to miss.

Bike headlights can definately be too bright, and cause temporary blindness in an oncomming driver's (or cyclist's) eyes. Car headlights are large extended sources. Bike headlights, especially HID and LED, are very small sources. When both are imaged onto the retina, the small source creates waaay higher light energy density on the retina making a localized blind spot much more likely.

Also, car headlights spread their light out over a much wider area than bike headlights, and cut it off below intended eye level for the safety of oncomming drivers. Bike headlights don't do that. Bike lights on a helmet are the worst thing to do, for on the road. Everything you look toward gets the full beam right in the eyes. Do YOU want a temporarily blinded driver comming around the corner behind YOU?

As I have said before, bike lights may be a small source but they are much, much further from on-coming traffic than automobile lights are because of our position on the road. Further away means more spread to the beam. More spread means less intensity to the on-coming traffic. That holds for bar mounted or helmet mounted lights.

It's called situational blindness and, yes, it is a real phenomena. I've experienced it from both sides. The guy that hit me while I was riding really, really didn't see me. He was as shocked as I was as I slide across his hood. The pedestrian I hit with my car I didn't see at all until she was standing in front of my car. People in cars can miss trains (I had a great uncle killed that way), a bicycle is pretty easy to miss.

Isn't the key to situational awareness the fact that your mind is on something else?

I mean if you are aware of the situation around you, and don't have your head in the clouds, it's pretty easy to see cyclists riding down the other side of a 6 lane wide road and be aware of them.

But the fact is that driving is made so comfortable that people simply zone out and tend to let themselves drift to other places (and yes, extreme emotional states can also factor in).

But if a motorist (or cyclist) is really focused on the task at hand, how can situational "un"awareness occur?

I was going to make a new post but this seems appropriate here. The other night I had an Elmhurst IL cop pass me going the other way who turned around and caught up to me at the next light and ask "what kind of light is that"? Told him it was a NiteRider MiNewt and how much I liked it for commuting - both seeing and being seen/able to point it at cars since it's a helmet mount - he seemed to be very interested in it. Generally speaking, for my commuter needs, the MiNewt has been a great light.

As I have said before, bike lights may be a small source but they are much, much further from on-coming traffic than automobile lights are because of our position on the road. Further away means more spread to the beam. More spread means less intensity to the on-coming traffic. That holds for bar mounted or helmet mounted lights.

I totally disagree. If a bike headlight has optics that focus the beam into as small a spot as possible, to "get more bang for the buck" for example, it can maintain higher lux in the central hot spot as a function of distance than a car headlight might (which is designed for a very wide output spread). Also, the decrease in the size of the image of the source on the retina can result in a much higher light [I]density[I] there for a small source like HID or LED. It can be painful.

Also, the difference in distance is minimal at best. One lane over.

"Further away" does NOT mean "more spread". It might mean more area covered, which is different than beam spread (which is an angular measurement), but that again depends on the reflector or lenses in a particular headlight.

I drive a big white Crown Vic at night, and there have indeed been times bicyclists' lights have been a mild irritant due to the brightness and being aimed at my eyes. Really, though, I am just happy that the cyclists are USING lights at night, and let it pass. There are ways to avoid being blinded by such lights, such as focusing one's eyes elsewhere.

As far as I know, there is nothing in the Texas Traffic Code requiring bicyclists to dim their lights for traffic, and I am not aware of any law regulating the aiming of cyclists' headlights. A peace officer IS expected to deal with hazards to public safety, whether there is a relevant violation of law, or not.

I have, in the past, used a helmet-mounted NR light to briefly pass a beam across the (presumed) visual field of a motorist, cyclist, or pedestrian, but I don't presently use a helmet-mounted light. I keep my MiNewts and Sigmas aimed low enough to be not too irritating.

Thanks for that consideration. I think those who use helmet lights on the road are just giving oncomming drivers, cyclists and walkers the finger. Total disregard for the safety of anyone else on the road, except of course, them (in their own mind). Just like those who drive SUVs and raised vanity trucks with headlights mounted so that they blast directly into the faces of all drivers of cars of rational height.

I don't know nor do I care if my head light bothers drivers when it hits them in the face. I use it so they see me and so I can see where I am going. If it affects drivers they can look away. It is not as if it is as bright as a vehicle high beams. Plus where I have it mounted I am unable to easily dim it. I ride a recumbent, there is no place to mount it on the handle bars. It is on the front T shaped piece at the front derailer mast.

I use the Cygolite Dualcross 300.

Thanks for illustrating my point so well. Don't be surprised when some driver extends YOU the same level of courtesy on the road. And by the way, the temporary blindness I'm warning against happens before the victim "can look away". Humans are hard wired to look toward bright lights at night. Too much light from too small a source causes temporary damage immediately, and the risk is to others on the road. Thanks a lot.

My gawd, I'm amazed that these helmet-mounted light using scofflaws are not being maimed, killed or cited by the bazillions! Somebody pass a law and save us! :rolleyes:

Please, get a grip.

My point must've gone right over your head. Again, there IS a law that requires motorists to go to dims for oncomming traffic. As bike headlights get more powerful, and to deal with those inconsiderately selfish (in my opinion) wearing headlights on helmets while riding on the road, I hope that law will be enforced.

Ignorant, inconsiderate lighting is just one more reason for non-cyclists to hate cyclists.

My bar light (MS900) is pointed at the ground so I can see where I am going. If it were up high enough to blind oncoming traffic it wouldn't do me any good. My helmet light is tiny in comparison (Blackburn Flea) and it may get someones attention but it's not bright enough to bother anyone.

And, cars dim their headlights thinking I'm a motorcycle or scooter all the time :)

Isn't the key to situational awareness the fact that your mind is on something else?

I mean if you are aware of the situation around you, and don't have your head in the clouds, it's pretty easy to see cyclists riding down the other side of a 6 lane wide road and be aware of them.

But the fact is that driving is made so comfortable that people simply zone out and tend to let themselves drift to other places (and yes, extreme emotional states can also factor in).

But if a motorist (or cyclist) is really focused on the task at hand, how can situational "un"awareness occur?

It is hard to believe that it can happen unless you've experienced it. When it happened to me (when I hit someone else), I assure you that my head was not in the clouds. I wasn't using a cell phone, I wasn't messing with the radio, I wasn't yelling at kids. I was making a left turn but I wasn't in a rush to do so. Traffic was low and I wasn't hurrying to make the turn. I was even the second car in line (the other car went straight) on a two lane road. The person I hit was wearing clothing that almost exactly matched the color scheme of the building she was standing in front of on the corner.

She literally appeared out of no where to me. I was moving slow enough that I only bumped her with my vehicle (moving at less than 5 mph) but it was enough to cause severe injuries that cost tens of thousands to treat. I can even picture the intersection today with everything there, except the pedestrian I hit. I can see the cars parked on the both sides of the road, the vehicle that was first in line, the cars that were on the cross street, even the yellow bus that was parked about half an block down the street I was turning onto. I can even see the moment of impact but I cannot see, and I never saw, the woman until I hit her.

We want to make someone who hurts us into the villain. It's human nature. But accidents do happen. It takes someone with serious mental problems to actively want to hurt another human. Those kinds of people don't last long in society. Most people are truly caring individuals who don't want to harm others. Most anyone who says otherwise is usually just blustering. As the old saying goes, talk is cheap.

I totally disagree. If a bike headlight has optics that focus the beam into as small a spot as possible, to "get more bang for the buck" for example, it can maintain higher lux in the central hot spot as a function of distance than a car headlight might (which is designed for a very wide output spread). Also, the decrease in the size of the image of the source on the retina can result in a much higher light [I]density[I] there for a small source like HID or LED. It can be painful.

Like shooting fish in a barrel:rolleyes:

If you disagree, then why do you run one of the brightest LED light systems available? You have a Magicshine 900. If bright lights are so dangerous, why did you buy one that is advertised to put out 900 lumens? The advertised brightness of these lights are nearly that of automobile lights. And that light is concentrated in a small space...just like the lights you rail against. There are far dimmer lights out there that would be 'safe' to use around cars and not blind drivers.


Also, the difference in distance is minimal at best. One lane over.

"Further away" does NOT mean "more spread". It might mean more area covered, which is different than beam spread (which is an angular measurement), but that again depends on the reflector or lenses in a particular headlight.

:roflmao2::roflmao2: "Further away" does NOT mean "more spread". :roflmao2::roflmao2:

Do you even read what you write? The only place you can get more area covered by the light is by spreading the beam over a wider area. The more beam spread, the less intense the light has to be at the center. And the further the light travels the more it spreads out.

Further...have we been here before:rolleyes:...look at the way car lights are aimed. The passenger side light (in the US) is aimed further down the road then the driver's side. This is so that you can illuminate the road, and travel at higher speed, without blinding other drivers. That light is even closer to oncoming traffic and aimed further down the road than a bicycle light typically is. Or are you worried about blinding other drivers with that one and intentionally aim your car lights down?:rolleyes:

My bar light (MS900) is pointed at the ground so I can see where I am going. If it were up high enough to blind oncoming traffic it wouldn't do me any good. My helmet light is tiny in comparison (Blackburn Flea) and it may get someones attention but it's not bright enough to bother anyone.

And, cars dim their headlights thinking I'm a motorcycle or scooter all the time :)

Well said.

This is a point that RapidRobert misses all the time. Bicycle lights aren't aimed nearly as high as car lights are. My bike lights are aimed roughly 2 car lengths ahead of me (about 30 feet). Anymore and the light doesn't do anything for lighting up the road so that I can see...and avoid...road hazards. My helmet light is only about 2 feet in front of my bar light.

I run lights that are arguably far brighter than the Magicshine or any HID. I've run a helmet light of some kind or another for around 20 years of varying outputs from around 200 lumens to 1500 lumens. One of my lights runs around 1500 lumens and I run 3 of those. (Yes, I'm bragging. Sorry:rolleyes:) I've had one motorist flash their brights at me in all those years of riding at night. I have flashed my helmet light across people's faces if they are trying to pull out on me at intersections (I don't have to do it as much with the 1500 lumen light. Sorry. Bragging again:rolleyes:) but those people are stopped and I only do it for my own safety. I don't make a habit of flashing my lights in the faces of moving oncoming traffic. I have no doubt that other helmet light users do the same. We aren't stupid:rolleyes:

How is this?

http://s134.photobucket.com/albums/q119/hotbike/photo_0022.jpg

You are looking at the headlight, with a Christmas Tree behind it, for comparison.

Yes, I dim this light. I also have amber marker lights and a helmet LED light.

Thanks for that consideration. I think those who use helmet lights on the road are just giving oncomming drivers, cyclists and walkers the finger. Total disregard for the safety of anyone else on the road, except of course, them (in their own mind). Just like those who drive SUVs and raised vanity trucks with headlights mounted so that they blast directly into the faces of all drivers of cars of rational height.I think the raised trucks and SUVs should definitely have their lights lowered. As far as helmet lights, you can point it down. When I'm in an area with a lot of cross traffic and it's likely that people are going to be pulling out in front of me, I'll point mine up and be fairly careful as to where it is pointing. Anyone that doesn't stop for a stop sign gets to see it. I also use it to get motorists to dim. Don't think 45 lumen are going to blind anyone, but it will annoy. I have desired a really bright helmet light for the idiots that don't dim after they get flashed with the helmet light a couple of times.

How is this?

http://s134.photobucket.com/albums/q119/hotbike/photo_0022.jpg

You are looking at the headlight, with a Christmas Tree behind it, for comparison.

Yes, I dim this light. I also have amber marker lights and a helmet LED light.

Now if you really want to be seen just town that Christmas tree around with you on your bike. :p I typically use only a bar mounted light around town, but I do have my helmet light with me just in case I have to get someones attention or in case I want to hit some trails later. I have set up my bike and walked down the road a ways and looked back to see how effective my lights are and having the bar light at full power is harsh to look towards. I run my bar light at 40% power most of the time when on the street which is still claimed to be 560 lumens, though this is an overinflated figure, and this gets me a long run-time too at this power level. At 40% level drivers still get a little twitchy so the light must be borderline annoying to them. Testing my light at a lower level, under 100 lumens, I found that I was not always noticed and drivers didn't give respect and would cut in front of me at times plus I couldn't see the road at all times particularly when cars were coming at me.

My point must've gone right over your head. Again, there IS a law that requires motorists to go to dims for oncomming traffic. As bike headlights get more powerful, and to deal with those inconsiderately selfish (in my opinion) wearing headlights on helmets while riding on the road, I hope that law will be enforced.

Ignorant, inconsiderate lighting is just one more reason for non-cyclists to hate cyclists.

Lets talk common sense based upon actual experience. Low-beams from cars and trucks bother me on dark narrow country roads...I can't recall a helmet mounted light (or any bike light for that matter) that has bothered me in the same fashion - and I have seen a lot of them. So tell us, how many of these mythical lights have actually caused you distress? How many have been documented to cause accidents? How many letters-to-the-editor, newspaper articles, magazine articles, blog posts, car forum posts, etc. can you cite where drivers are complaining about being blinded by bike headlights? Having an opinion is fine, but how credible your opinion is requires more that just your opinion.

Yes, but it's 50 watts with a full cutoff below eye level. If you have ever had a car with misaligned lights coming towards you, you will know that even low beams can be blinding. This is my biggest gripe about bike lights - they almost all have a circular beam instead of a proper shaped beam with cutoff. 10 watts can be irritating, 30 watts can be blinding, if aimed wrong. 1000 watts can be fine, if aimed right.

Mainly what car lights do when going to low beams is not to dim but to move the beam so that they are not shining up and into other drivers' eyes.

This is completely correct about brightness and wattage, especially since HID (aka xenon) lights don't each consume more than about 35 watts, but are at least twice the intensity of halogens and conventional tungsten lights. It's not just more lumens per watt, but much more effective control of light distribution, for the HIDs. Many of them have a motor that lowers the light when the car tilts up.

What's not right is moving the light when going to low beam. While some headlight systems do have a vane that moves to impose a cutoff in low beam, it's only for systems with HID highs as well as lows, and that's not all headlamps.

It's entirely possible for a bike light to deliver as much brightness to a driver's eyes as a bright automotive headlight when not aimed right. It's much less common now for car lights to aimed wrong, while bike lights have no standards or limitation on aim point or light distribution, at least in the USA. We might be the worst-offending sources of glare on the road!

that day is here for some people. I've been riding in a group at night and opposing drivers turned on their brights. OTOH, many drivers are idiots, and some apparently turn on their brights when they don't understand what they are seeing. They get the full helmet light in the face treatment.

Actually aggressive use of high beam can be considered aggressive driving, and hence can be a citable offense for a car driver. Why not the same for a cyclist? Be careful with that weapon.

I would like to see my light from a car, but it's dyno powered and I don't really trust anyone to ride my bike. I have had a couple of drivers wait for me for a very long time. That indicates that it's bright enough to confuse them about the source.

Car lights are nearly blinding, even on low. On bright, the effect is extended, and the after-effects are worse. I am approximately half as bright as a car at speed. I'm sure it's at least a little blinding, and that's exacerbated by the spread of the lights. I do have the most tightly focused lens I could find.

I'm very surprised by this, unless you ride a very low slung recumbent trike. How bright a car light looks is a function of how high off the ground your eyes are, because of the cutoff and the light distribution design. Even the past generation of sealed beams have a decent cutoff, but not as good as Euro-style halogens or modern HIDs. On an upright bike of nearly any type your eyes are higher off the ground than for most sedan drivers. In a minivan, SUV, or light truck you eyes are at least as high as on a bike. Either you are seeing a LOT of misaligned headlights (many more than I see, and having been involved in designing headlamps I do notice), or your eyes are extra sensitive to light.