Electronics, Lighting, & Gadgets - Is Fenix l2D too bright for cars?

I had mine on the 2'nd highest mode ( 110 lumens?) and an oncoming car flashed me with his brights. Is this light really blinding to drivers or was he just confused by it?

I had mine on the 2'nd highest mode ( 110 lumens?) and an oncoming car flashed me with his brights. Is this light really blinding to drivers or was he just confused by it?

Perhaps you have it aimed a little high. The primary function of lights is to illuminate the road in front of you. Serving as a warning to other road users is secondary.

Other than that why worry about what the drivers think? Unless you are throwing as much light as I do (way, way, way more than 110 lumens), you aren't even close to what the other cars on the road are putting out. I wouldn't worry about it. At least he saw you:)

How far in front of you should the light illuminate? Is there some kind 3-second rule of thumb?

It would be logical to have the beam's "hotspot" landing on the pavement. How far ahead, would depend partly on whether it actually shows up. So for an L2D on medium mode, maybe 15-30 meters out.

Because the light is emitted through a small aperture, it looks pretty intense, so that may be why someone flashed their lights at you. If you think about it... you can stare straight at a 4-foot fluorescent light fixture. But if all that light were being emitted from a small area, instead of a large one? Yeah. It would be much too intense to look at comfortably.

I used to get that too. It even happened with my very first lighting system, which was just a basic 5 watt MR-11 made by nite-hawk. You cannot tell me that they were blinded by that light!! I know from time to time, I will brighten my car's high beams just to confirm something on the road ahead, then dim them again if needed. I cannot help to wonder if that is what other drivers do too.

Don't worry about it...

I had mine on the 2'nd highest mode ( 110 lumens?) and an oncoming car flashed me with his brights. Is this light really blinding to drivers or was he just confused by it?

He was just confused by it. The driver probably momentarily flashed the high beams to confirm what he saw.

some times they are not flashing at you, but they flash to the slowmoes in front of them to move out of the way.

other times when it seems like the flash for no reason, is to trigger the street light sensors, to keep the lights unchanged, or to change faster to green (those that believes they can imitate the light flashes from the emergency vehicles.)

i saw one of that a couple of days ago, i was LMAO.

some times they are not flashing at you, but they flash to the slowmoes in front of them to move out of the way.

other times when it seems like the flash for no reason, is to trigger the street light sensors, to keep the lights unchanged, or to change faster to green (those that believes they can imitate the light flashes from the emergency vehicles.)

i saw one of that a couple of days ago, i was LMAO.

Oddly enough, one of the lights on my way home will break cycle as I ride up to it. I have a pair of Dinotte 200L. They're not flashing or anything, just both on high power. It's weird, but convenient. Just the one light out (out of three). So perhaps there is something to that?

get used to it. it happens

flashlights and bike lights do not have the advanced reflectors to throw light below the drivers
eyeball. no matter what you do, if a driver fixates on your light it will look bright to them. ignore them.

other times when it seems like the flash for no reason, is to trigger the street light sensors, to keep the lights unchanged, or to change faster to green (those that believes they can imitate the light flashes from the emergency vehicles.)

I'd think they would have to flash their headlights pretty fast to get a street signal to change - aren't they designed to react to emergency vehicle strobe lights set at a specific frequency?

You need to slap on at least another few hundred lumens before you can really get a car's attention.

I'd think they would have to flash their headlights pretty fast to get a street signal to change - aren't they designed to react to emergency vehicle strobe lights set at a specific frequency?

I believe that's normally done using an infrared preemption system on the emergency vehicle.

I believe that's normally done using an infrared preemption system on the emergency vehicle.

Yup, if you search the web, there's instructions on how to build em. (i have no idea if they actually work or not).

Sometimes i think i'm getting flashed but it's actually just the car going over a big bump.

you need to slap on at least another few hundred lumens before you can really get a car's attention.

+1.

Car headlights have very complex lenses to keep the light low and away from drivers eyes. Lower on the side of oncoming traffic and higher on the other side too. If you put your car lights on and drive up to a wall this is very obvious.
The Flashlight, and most good bike lights with a symetrical beam send more light up high. The symetrical beam is a good thing for a two wheel vehicle. A car beam will dissapear on one side when you bank the bike. The symetrical beam not as much.

Don't worry about it, if you have the aim correct for your riding speed, that's all you can do. If there is not much traffic, having the light on high and switching it to a lower setting when you know the car can first see you lets them know you are not still on high beam.

I always assume they're flashing me and my L2d to show "cool lights!"

I've seen other riders around LA with L2Ds at night and dusk, on flash and turbo, and I think that it's unlikely to be blindingly blight to a car driver unless you're really close (<10feet) and aim it directly into their eyes. I found the oncoming car traffic and other cars on the road WAY brighter than the L2D - although I definitely noticed the L2Ds bright spot very quickly.

It would be logical to have the beam's "hotspot" landing on the pavement. How far ahead, would depend partly on whether it actually shows up. So for an L2D on medium mode, maybe 15-30 meters out.

Because the light is emitted through a small aperture, it looks pretty intense, so that may be why someone flashed their lights at you. If you think about it... you can stare straight at a 4-foot fluorescent light fixture. But if all that light were being emitted from a small area, instead of a large one? Yeah. It would be much too intense to look at comfortably.

I looked down at my automatic transmission gear indicator today, reading it starting close to me and going to the front of the car it says-

L2D R N P

sorry........:o

I have a 2 AA LED flashlight that puts out 115 lumens and I can't imagine that blinding a driver unless it was close up and aimed right in their eyes. Don't worry about blinding drivers with that little light, just aim the light where you can see the road best and ride on.

Other than that why worry about what the drivers think? )
Perhaps because it's not cool to blind people with your lights?

The idea I guess is to have enough light to still be able to see the road with oncoming traffic, be noticed by them, and not blind them in the process.

I can't imagine that these lights are really equal to a car headlight on low beams

It's the lens. It's the lens. It's the lens.

The flashlight looks like a high beam as it sends more light up into the drivers eyes. It may not blind them, but they think you can dim your lights, so they flash their lights at you.

You can simulate the car beam by taping off a very small part of an L2D at the top. Aim it at a wall and use something with a straight edge to see how to block off a little.

Flashlight beam sends light all directions equally. Most bike lights too, not all.

http://img411.imageshack.us/img411/8871/26590151eh9.png

Car lights chop off the top of the beam with complicated lenses to keep the light out of drivers eyes, and down on the road. But are a lot brighter than an L2D.

http://img411.imageshack.us/img411/1796/38121589eg7.png

Got my L2D today.. Looks very nice.. The strobe is blinding..

2manybikes is correct, it's the beam pattern.

two ways to get a higher focus/less spill beam for the flashlights is to put a convex lense on the head, and to make a deeper reflector cone area with cut offs.

just blocking the light with cutoffs on the current heads isn't too much good.

ehh they only see you for few seconds at a time, your the one that has to see the entire time. Not worth trying to please people you don't even know over it.

Run the brightest/best setup you can afford.

just blocking the light with cutoffs on the current heads isn't too much good.

That was my conclusion as well. I set up a 1/3 cutoff on my MRV SK, and on my way home last week, I parked my bike on a dark highway and marched up the road about 90 meters to see how it looked.

Then I went back to the bike, flipped the flashlight upside down so the cutoff was effectively neutralized, and marched back up the road to the same spot to look again. I couldn't tell any difference.

Also, even an automotive-quality cutoff won't save people from getting blasted by the full intensity of the light, if the vehicle is coming over a rise at the victims. In that regard, cyclists have more control than motorists, since you have manual control over the aim of your lights. If I ever build a DIY light system, it IS going to have independently-switched "high beam" emitters aimed like an automotive high beam.

ehh they only see you for few seconds at a time, your the one that has to see the entire time. Not worth trying to please people you don't even know over it.

Run the brightest/best setup you can afford.

You're only respectful to people you know?

You're only respectful to people you know?I agree with you Ziemas; I am a bit concerned by some of the replies here. Would not this logic apply to both sides of this story? I believe there is a reason cars are legally bound to have high and low beam headlamps.

Aim your lamps down then read this Wikipedia article on headlamps (http://en.wikipedia.org/wiki/Headlamp#Optical_systems). The link will take you to the section on Optical systems and explain different approaches to high and low beam optics. It is not rocket science and can be understood (if you wish.)

The problem is there are no bicycle lights that take this into account. As road users I believe we ought to be concerned about blinding others. For this reason I'm putting a small motorcycle headlamp on my bicycle. It will have the same wattage as my MR-16 halogen from last year, but I will not be blinding other drivers with it. I will be wiring controls for the high beam and plan on using it; sometimes to get someone's attention -- but as a rule to operate by low beam.

The problem is there are no bicycle lights that take this into account.

Actually, there are a few that have shaped beams, notably the L&M Seca line and several dyno headlights. One of the main problems with bike lights is simply that all the light is coming from a small source, so even the spill beam looks intense.

Speaking for myself, if I'm on pitch-dark 2-lane highway and I'll be facing other people for a while (a daily occurrence on my commuting route), then I will either dim or turn off my main lights, even though they're properly aimed, and rely on my helmet light, with the hot spot aimed away from the oncoming people.

This tactic has its ups and downs. On one hand, it reminds motorists to dim their headlights for me, when I do so for them. :) On the other hand, if I turn off my bike-mounted lights completely, the sudden drop in illumination apparently makes me practically disappear, and they turn their high beams back ON, either because they think I turned off the road, or they're trying to determine where I am. As a happy medium, switching off my Dereelight DBS super-thrower and reducing my Seca 700 to 25% power is a safe bet. This also applies to people who've passed and are now getting my lights in their mirrors.

In better-lit situations, or on divided highways, I play it by ear. Unfortunately, the people who need me to dim my lights the most, are the people I can't see until I'm right on top of them: pedestrians who aren't packing 1600-3500 lumens of their own, and whose vision will be seriously affected by my lights. In the event I can detect them, however, I take special care. Fortunately, there aren't too many pedestrians wandering the highways, and I avoid MUPs completely.

You're only respectful to people you know?

Sure I respect everyone, but when my safety is on the line when I'm out there at night chuggin along at 20-25mph, I'm not exactly eager to dim my lights for on coming cars.

Before I got my bright light, I had a simple bike light (old 10watt halogen), going along a 2 lane road, with a friend behind me. A on coming car following another car appairently didn't see us, and he overtook the car in front of him. His driver side mirror came within 3 inches of my handle bar as he passed us at 50+mph in the opposite direction. I'd believe that if he can SEE me, he wouldn't attempt a pass like that. This particalar road had 6-8" right of the white line so there wasn't awaywhere to go. The next day I order my MTE P7 light, this was back in June when it gets dark at 8:15pm.

I believe the CA driving book, it state if you see high beams from the opposite side, you look at the white line on the right side of the road to guide you pass the on coming cars, away from the light. So if my light is too bright, they they should be looking away from it.

If I spot a pedestrian in the distance, I'll cover the right half of my light so they aren't blinded for the entire time it takes me to pass them.

Actually, there are a few that have shaped beams, notably the L&M Seca line and several dyno headlights.I'll take your word on this as I admit I haven't researched it. Maybe I ought to revise my statement to include the set of lights typically discussed here on BikeForums, such as high-powered LED flashlights and such.


One of the main problems with bike lights is simply that all the light is coming from a small source, so even the spill beam looks intense.Are not halogen filaments also small? I'm thinking of MR16s and regular car headlights here. I don't think the source of the light is the problem but as noted on the Bicycle Lighting Systems website the answer lies in the size of the reflector.


Most of my ride is on a [mostly] well-lit section of urban main street; Euclid Avenue through East Cleveland if you wish to look it up. There are sections that the street lights are out but for the most part it is well lit. Also, traffic is light when I roll through at 0600 to 0700 in the mornings. The afternoon is different as traffic is much heavier.

Are not halogen filaments also small? I'm thinking of MR16s and regular car headlights here. I don't think the source of the light is the problem but as noted on the Bicycle Lighting Systems website the answer lies in the size of the reflector.

That is my point as well: the reflector of a bicycle light is small. Even if the "hot spot" of the beam is aimed completely onto the ground, the peripheral "spill beam" will still look relatively intense, simply because it's concentrated into a small aperture.

In the experiment with my MRV, I had its hot spot landing completely on the ground, with 1/3 of the lens obscured as a cutoff. It's not that bright a light to start with, either. From 80 paces, even the small portion of light that was escaping above the cutoff looked quite intense to me as a pedestrian on a pitch-dark highway. To a motorist, with a tinted windshield and thousands of lumens of foreground illumination, I don't think the MRV SK would be a problem unless I aimed the hot spot of the beam up at them, instead of down onto the ground. It's a medium thrower, so most of the power is going into the hotsot.

http://i240.photobucket.com/albums/ff237/mechBgon/IMG_0083.jpg

http://i240.photobucket.com/albums/ff237/mechBgon/cutoff1.jpg