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How Bright Is Too Bright

This topic contains 96 replies, has 30 voices, and was last updated by  Mick 10 mos, 2 weeks.

Viewing 17 posts - 81 through 97 (of 97 total)
 
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UnrealMachine

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Oct 16 2013 at 8:22pm #

Mick wrote:A thought: if your light is harder on the eyes than the low beam headlight on a new car, that’s too much, IMO. That isn’t uncommon.

Probably more obnoxious by being smaller area light source, pointing at people’s eyes, and blinking than actual brightness.

The lighting needs for a car and a bike are different. WAY different. First off, car lights have to meet Federal Motor Vehicle Safety Standard 108. The maximum number of watts (supplied at 12.8 volts) is 55-70. Depending on the light source and luminous efficiency, you are talking between 1100 and 3000+ lumens. Car light heads are installed in a factory (standardized) and have cutoffs, but if you catch the car coming over a hill or around a bend the light will still be shining in your eyes. Those designs conform to the dimensions of vehicles and the dimensions of the roads they use. Travel by bicycle, relatively speaking, does not enjoy those same standardized parameters so any comparison to such is already starting out on a very uneven playing field.

Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense. Is it so hard to look away from a bright light (unless you plan on walking/driving straight into it)?

Do a search for:

1) No. of accidents caused by a cyclist’s light being too bright =zero;

and

2) No. of accidents caused by insufficient or non-existent cycle lighting = thousands

So do you want to buy a lower lumen light to “protect” all those poor road users from your “blinding” light? Or do you want to prevent an accident by being sufficiently lit?


Drewbacca

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Oct 16 2013 at 9:26pm #

salty wrote:http://www.legis.state.pa.us/cfdocs/legis/LI/consCheck.cfm?txtType=HTM&ttl=75&div=0&chpt=35&sctn=7&subsctn=0

It doesn’t say that it has to be turned on or otherwise functioning. ;)


salty

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Oct 16 2013 at 10:08pm #

http://www.legis.state.pa.us/cfdocs/legis/LI/consCheck.cfm?txtType=HTM&ttl=75&div=0&chpt=43&sctn=2&subsctn=0


edmonds59

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Oct 17 2013 at 5:35am #

I don’t ride in the dark very often, but the other morning I had occasion to, at 6:00 am.
Nite rider 650 lumen on steady on front (low setting) pointed to a pool of light 10+- feet in front to see the road, with a Blackburn voyager 1 watt set on flash beside it. On back a basic Blackburn blinky set on steady with a Planet Bike superflash on blink right next to it. I felt quite adequately lit. Also w/a viz/reflective construction vest and a reflective leg band.


jonawebb

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Oct 17 2013 at 8:31am #

@edmonds, that’s pretty damn bright. For comparison, Peter White photographed various headlight beams in a standard setup here.


WillB

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Oct 17 2013 at 9:31am #

Apparently we’re all supposed to have amber reflectors on the sides too. Anybody actually have these? I’ve got white reflectors in the wheels on some bikes, but no amber.


RustyRed

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Oct 17 2013 at 10:29am #

WillB wrote:Apparently we’re all supposed to have amber reflectors on the sides too. Anybody actually have these? I’ve got white reflectors in the wheels on some bikes, but no amber.

<—- *quickly scribbles on her white reflectors with an orange marker*


Mikhail

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Oct 17 2013 at 10:34am #

UnrealMachine wrote:Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense.

Well, there is some problems measuring everything in lumens (http://en.wikipedia.org/wiki/Lumen_%28unit%29). While it’s defined as 1 lm = 1 cd·sr (http://en.wikipedia.org/wiki/Candela, http://en.wikipedia.org/wiki/Steradian) and candela is a base unit of luminous intensity weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths), the model itself uses continuous function with a concrete behavior. Xenon lights and especially LED do not confirm to it. That is why very often people complain that xenon/LED lights are brighter and at the same time you don’t see much with those lights. Earlier LED lamp for household were so bad that with a lot of brightness you almost in darkness. And this is because of the fact that spectrum is shifted to the blue side and pupil is closed but there is not enough green/yellow part that eye could not see good enough.

So in additions to lumens we need a spectrum of a particular light to be able to estimate how good is light.

PS red light does not affect night vision and that is why using more “natural” warm light (shift to the yellow part which is possible if there is enough red part of spectrum) makes transition from light to darkness usually easier.


Mick

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Oct 17 2013 at 11:22am #

@unrealmachine Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense

We’re talking about oragnes and apples here.

I’m talking about something being seriously irritating. You’re saying that because you ahve not heard of a death (there are reprots of epileptic seizures being caused by lights) that they are not obnoxious? If you are, I believe you are wrong.

I’ve had to stop on trails until the light shining in my eyes was past. Many times.

I’ve certainly shouted angry things at cyclists that were blinking lights in my eyes. I don’t beleive I’m epileptic or anything but I am sensitive to blinking lights somehow.

The comforts of car drivers is not my top priority , of course, but I’d rather not have the word bicylist to be always (and justifiably) preceded by “obnoxious.”

Cars have high beams that are sometimes misused. There are rules against that. Given that tickets are rarely, if ever given for that, it’s surprising high beams aren’t misused more.

I looked for a report on fatalities inappropriate high beam use. Couldn’t find any. Not one.

That doesn’t make misuse of high beams OK, somehow. Nor is having blinding, blinking headlights on a bike OK.

So you might disagree with what I say, but calling it “nonsense?” Unreal, for sure.


UnrealMachine

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Oct 17 2013 at 1:16pm #

edmonds59 wrote:I don’t ride in the dark very often, but the other morning I had occasion to, at 6:00 am.
Nite rider 650 lumen on steady on front (low setting) pointed to a pool of light 10+- feet in front to see the road, with a Blackburn voyager 1 watt set on flash beside it. On back a basic Blackburn blinky set on steady with a Planet Bike superflash on blink right next to it. I felt quite adequately lit. Also w/a viz/reflective construction vest and a reflective leg band.

How fast were you riding? If you can only see 10 feet in front of you and are traveling at 15 mph (22 fps), you will have less than 1/2 of a second to identify, react and maneuver you bike around any potential obstacle (pot hole, debris, etc.) in your path that may not be visible without lighting.


UnrealMachine

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Oct 17 2013 at 1:21pm #

Mikhail wrote:

UnrealMachine wrote:Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense.

Well, there is some problems measuring everything in lumens (http://en.wikipedia.org/wiki/Lumen_%28unit%29). While it’s defined as 1 lm = 1 cd·sr (http://en.wikipedia.org/wiki/Candela, http://en.wikipedia.org/wiki/Steradian) and candela is a base unit of luminous intensity weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths), the model itself uses continuous function with a concrete behavior. Xenon lights and especially LED do not confirm to it. That is why very often people complain that xenon/LED lights are brighter and at the same time you don’t see much with those lights. Earlier LED lamp for household were so bad that with a lot of brightness you almost in darkness. And this is because of the fact that spectrum is shifted to the blue side and pupil is closed but there is not enough green/yellow part that eye could not see good enough.

So in additions to lumens we need a spectrum of a particular light to be able to estimate how good is light.

PS red light does not affect night vision and that is why using more “natural” warm light (shift to the yellow part which is possible if there is enough red part of spectrum) makes transition from light to darkness usually easier.

Good post. I agree that the colors can be significantly improved upon. Some of the better lighting systems offer this.


UnrealMachine

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Oct 17 2013 at 1:35pm #

Mick wrote:@unrealmachine Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense

We’re talking about oragnes and apples here.

I’m talking about something being seriously irritating. You’re saying that because you ahve not heard of a death (there are reprots of epileptic seizures being caused by lights) that they are not obnoxious? If you are, I believe you are wrong.

I’ve had to stop on trails until the light shining in my eyes was past. Many times.

I’ve certainly shouted angry things at cyclists that were blinking lights in my eyes. I don’t beleive I’m epileptic or anything but I am sensitive to blinking lights somehow.

The comforts of car drivers is not my top priority , of course, but I’d rather not have the word bicylist to be always (and justifiably) preceded by “obnoxious.”

Cars have high beams that are sometimes misused. There are rules against that. Given that tickets are rarely, if ever given for that, it’s surprising high beams aren’t misused more.

I looked for a report on fatalities inappropriate high beam use. Couldn’t find any. Not one.

That doesn’t make misuse of high beams OK, somehow. Nor is having blinding, blinking headlights on a bike OK.

So you might disagree with what I say, but calling it “nonsense?” Unreal, for sure.

You keep misusing the word “blinding”. Additionally, you infer that (your definition of) “blinding” lights should be removed or possibly legislated out of use. Meanwhile, there are only very specific circumstances in which a light can truly be menacing, and they have to do with the aim, proximity of those affected and the reactions of those affected. It could be an issue with a 1500+ lumens light or a 300 lumens one.

For road use, which I am focusing on here, where oncoming traffic is not directly in line with the cycling light, the idea of extrapolating experiences from a trail ride (where one is almost directly in line with oncoming cyclists/PEDs at times) to a road ride is not particularly applicable or useful. Oncoming traffic should not be in the direct hotspot of the light at close distances for any considerable amount of time.


reddan

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Oct 17 2013 at 1:44pm #

This is one of the reasons I’ve become fond of headlamps that include an upper cutoff, such as the many European lights that conform to the StVZO standard. Barring significant misalignment, the majority of the light will be focused where it needs to be in a road or cyclepath situation, and you won’t be blinding/annoying oncoming traffic (automotive or otherwise).

Another benefit to the StVZO lights is that their asymmetric optics tend to focus the light downwards, not just block some of it, so you get more effective illumination for less power consumption. Symmetric lights are great in an offroad environment, especially if you’re riding singletrack in darkness; on pavement, though, I see little need to illuminate much of anything over my head level.


Ohiojeff

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Oct 17 2013 at 2:00pm #

byogman wrote:

What prevents you from using your 900 lumen light as a flashing unit on a regular basis?

Just laziness and frankly a dislike for strong flashing lights. For the rear blinker there’s the justification that people continuously need to be aware. In front it’s really only helpful in route crossing/joining scenarios. But I suppose those are probably frequent enough that I just ought to do it anyway.

I have a 900 lumen light and I use it in flashing mode near sunset and during twilight to draw attention to me, however, I switch to solid mode once I deem it to be “dark.” The reason is that even though I have it mostly aimed down, it makes ALL of the reflective street signage for some distance in front of me look as if they are flashing on and off. It’s eyecatching, but I also fear it might be distracting for drivers. In solid mode I almost never have it running the full 900 lumens, I only need that on unlighted trails. Usually the medium or low light modes are fine on city streets.

I discovered this when I lived in Pittsburgh and would come into downtown via the jail trail. The light was making all the of the big green directional signs on the Parkway East near Grant Street appear to be flashing. I don’t know if the angle of reflection allowed that effect to appear to cars on the parkway, but I figured they didn’t need to be distracted looking for the source of the light.


Drewbacca

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Oct 17 2013 at 2:12pm #

UnrealMachine wrote:
Good post. I agree that the colors can be significantly improved upon. Some of the better lighting systems offer this.

Cygolite is a good example, their lower “metro” series has cooler colors compared to their higher end and warmer “expilion” series.


edmonds59

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Oct 17 2013 at 2:46pm #

@Unrealmachine – re; speed: I don’t know, I don’t pay attention to speed, I toodle (i.e., generally under 15 mph.). I rode to the comfortable speed/sight distance of the lights, not vice versa.


Mick

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Oct 17 2013 at 8:11pm #

UnrealMachine wrote:

Mick wrote:@unrealmachine Until someone posts an actual accident *caused by a cyclist’s light that was too bright* then all of this “blinding” talk is all nonsense

I’ve had to stop on trails until the light shining in my eyes was past. Many times.

You keep misusing the word “blinding”.

Tell me please, oh wise one, how to use the word “blinding.”

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