LED's... White

Why is it that White LED’s are blue-ish (6000K) , very bright, but you can’t see a thing with them? Do I need blue-ish LED eyeglasses?

Are you referring to the LED DRLs on some newer vehicles?
If so, they are not designed for anything other than allowing your vehicle to be seen by other vehicles.

DRLs–whether they use LEDs or not–are not designed to illuminate the road in front of you.


DRL=Daytime Running Lights
Those are the default lights that appear on the front of newer cars when you start the engine, but the headlights are not turned on.

I’ve noticed that too…with flashlights.
I can see much more with a good ol’ incandescent or halogen.

It has to do with the way your eyes handle light frequencies,your eyes dont do that good with blue light.We do better with something approaching the wavelengths in indirect sunlight.Anyone care to venture what color we percieve the sun?-Kevin


So at 6000kevins which is close to daylight, we can’t see the road. Kevin, can’t you do something about it. Our sun is Yellow, not blue.

Daylight color temperature varies during the day. As the sun’s angle changes, the lightwaves have to penetrate the atmosphere for a greater distance, so the blue waves are absorbed more, lowering the color temperature when the sun is lower in the sky. Even at noon, the color temperature does not reach 6000K.

Costco has a pair of LED flashlights for $30 that are 500 lumen. Turn one of those on at night in the yard, its like switching on the sun. Incredibly bright. Probably too bright for headlights, even high beams.

I put a bunch of HFreights, 9LED, freebie lites on my scooter, I have 2 pointed to the right for drivers who want to run an intersection, and pointed beyond my highbeam. I also have 2 whites facing towards the rear. Can’t see a thing with the LED’s/ I kept the halogen headlights, although weakish. I can see the pavement.

I gotta go to Costco to pickup BP pills. I am going to look at their LED flashlights. Thx @keith/

Our sun is Yellow, not blue
Close but no ceegar. The sun is white as it is comprised of all wavelengths. We see it is “yellow” here on earth because of the scattering effects of our atmosphere. Our sun happens to be fairly well balanced emission across the visible wavelengths.

LEDs use phosphors to broaden the emission but they are still fairly distinct wave bands of emission. The “white” leds use these effects along with the understanding of the relative sensitivity of your eye to various wavelengths, to make them appear “white” to your eye.

longprime, it is probably illegal to have rearward facing white lights. I understand the motivation but it may be working against you. People’s eyes are far more sensitive to the red portion of the spectrum and your brain is highly sensitive to motion or change. Assymetric flashing of a red light would be far more attention getting than a CW white light. Ever see those brake lights that flash at changing rates on the back of motorcycles? Grabs your attention immediately as the brain is keenly tuned to anything that might be a threat to our welfare. They sell them for bicyclists too, often a simple 50% duty cycle, high rep rate flasher.

I have a theory about red lights on bikes: You’re gonna read it here first.

In the county roads, early in the morning or late dark night, bikes are vulnerable to bit from the rear. Why is that a bike that is on the right edge of the road on a designated bike lane gets wipedout? It is because a driver sees the bike’s red tail light and the driver believes instinctively that he is in the left lane because he is not aligned with red tail light ahead. The driver then corrects his driving to be directly behind the bike and unfortunately has overtaken the bike when he realizes his mistake.

The same reason why white lights are illegal facing rearward makes an in-attentive driver confused in the dark when coming upon a single red tail light.

I have a theory about adult bike riders too, they are all a bunch of idiots. You see a 13 year old boy, at the height of his impulsive, immature front brain etc, and he won’t do the stupid things an adult bike rider will do.

You don’t see 13 year old boys riding down the center of a lane on a two way country road, refusing to pull over to the side to let traffic back up behind them, pull out into a lane of traffic without any regard to a vehicle 10 feet behind them going 30 mph and other stupid moves, but adult bike riders, they seem to think that they have some special right of way.

Don’t disagree you. My bike partner is like that, but he refuses to ride on country & town roads. He would rather hog the bike lane, ignore the crosswalk signals, doesn’t yield to pedestrians, etc. I like to stay about 50-100 feet behind him, inorder to call his wife.

Me, I always, give the yield to anyone who is bigger than me. But I want that bigger guy to know that I am here and want to be seen. I also have lawyer’d up.

Didnt say our sun was blue(and by the way-the light is more white,then yellow,a prism will split sunlight into its constitute colors,yellow included-sunlight is white)-Kevin


I flagged your flaming post because bicycles are regarded as motor vehicles in just about every location I can think of. Bicyclists are supposed to behave the way that you complain about. It’s short-tempered drivers who need to learn how to deal with this, while developing some emotional maturity.

I wish I could have flagged it as “off-topic” as well.

The “white” LEDs are about useless on Red Reflectors. and not so great on White.

FYI, My issue with White LED’s is a transference of my experience on a Bicycle. The LED lights on my bike is so that I can be seen from the front for crossing cars, and from the rear for tired, sleepy, and DUII drivers.

Rarely do I ride a bike at night because of oncoming traffic causes night blindness(?), with the worse occasion from the super brights helmet LEDs-almost landed in Puget Sound.

My bike partner is an true idiot on a bike and plain stupid when he’s behind the wheel. . You should see him in his pickup-I refuse to be his passenger…

Whitey I don’t really care whether you flagged me or not, but I do respect you for owning up to it. I don’t think that expressing my opinions about the morons I see riding bikes and stopping all the traffic reaches the level of abuse, though I’m sure that more than a few who read it are not happy with it.

One nearby community has bike lanes, but the riders, who are riding for recreation, not transportation or commuting and could easily use the bike lane, choose instead to use roads that do not have bike lanes instead, and they ride down the middle of the lane, not on the side of the road.

If states consider bicycles as motor vehicles, why aren’t they registered with the DMV? Why are they banned from freeways? Just because they are authorized to use public roads does not mean the state considers them motor vehicles. My state does not consider farm vehicles to be motor vehicles as such, but they are allowed to use the roads.

BTW, I have a bicycle and ride it regularly as part of my exercise program, I just stay off the busy roads, stay on the side of my road and I watch out for cars and stay out of their way. Pretty much the same way I road a bike when I was 12, just not as fast.