The Future of Light is the LED | Hacker News Reader

The Future of Light is the LED

wired.com

41 pointsdangrossman49 comments

I'm surprised behind the huge push behind a "soft yellow" colored bulb. The articles makes a claim that humans prefer the yellow/orange glow due to prevalence of fire as lighting.

But I don't see a single mention of the color termperature of pure sunshine, which is much, much closer to pure white (5500K).

Flourescent bulbs that glow at 5500K are considered "pure white" [0] and seem to be demonized in the article as too harsh.

I think this is a case of old folks that grew up under incandescents and prefer them purely because they grew up with it. As Steve Jobs has mentioned [1] (about keyboards), we just need to wait for them to die out eventually.

[0] http://www.pse.com/savingsandenergycenter/ForHomes/Publishin...

[1] http://orangejuiceliberationfront.com/theyll-die-out-eventua...

I like the sun just fine -- when I'm outside during the day. However, the color of light is important to the human sleep cycle. If you fill your house with sun (blue) colored lights, you're going to shift your melatonin production later and may have a hard time going to sleep. Humans have evolved with blue light during the day and yellow light at night for quite some time, so I think it's more than just a nostalgic preference.

From "Effect of Illuminance and Color Temperature on Lowering of Physiological Activity":

"...we surmise that the effect of color temperature is greater than that of illuminance in an ordinary residential bedroom or similar environment where a lowering of physiological activity is desirable, and we therefore find the use of low color temperature illumination more important than the reduction of illuminance. Subjective drowsiness results also indicate that reduction of illuminance without reduction of color temperature should be avoided."

http://www.jstage.jst.go.jp/article/ahs/18/4/18_117/_article...

This is why I use Flux on my Mac: http://stereopsis.com/flux/

I think the reason fluorescent lightning looks bad is not the color temperature, it's the narrow spectrum of emitted light.

Fluorescent doesn't actually have a narrow spectrum. What it has is very strong peaks by certain lines.

i.e. most of the light is UV, which is converted to other colors by phosphors - in precisely the same method LED uses. If it stopped there it would be great.

But it also makes visible light in narrow peaks, and this messes with the color, so they compensate by adjusting the phosphors for the complementary color, but that hurts the color rendering.

And the flicker.

Modern "electronic" fluorescent ballasts don't flicker, at least when not broken. (They use a frequency that is high enough that the phosphors' glow hasn't stopped before the cycle is over). The old "magnetic" ones did, but those really ought not be used anymore. They're less efficient and often flicker and hum.

Bulbs at the end of their life can flicker, but those of course should be replaced.

I'm with you. I hope that we aren't forever doomed to a world of yellow light by the preferences of past generations. I'd love to buy some dimmable cold-cathode fluorescent lights, but I can only find them in ~2700K.

I don't know if it's been experimentally verified, but to my perception, color temperature is a lot more complex than blue for day, yellow for night. I find that as light levels approach blackness, I prefer higher color temperatures once again (possibly mimicking moonlight). I have many more ideas for optimizing lighting and color temperature throughout the day, which I hope to apply in the next phase of my current startup.

Moonlight is actually 4100 K, colder than incandescent, but warmer than regular daylight.

My (little) kids make a big fuss if I try to put in any "sunlight" spectrum bulb of any sort. They complain that it is bluish, cold, and "yucky." Their favorite is any intense halogen (not the blue headlights, but indoor yellow-white), which seems to me to have a color temp of 2700-3300 or so. They also like ordinary incandescent bulbs.

Natural sunlight seems yellowish-white to me when you are in the warm sun, and only feels bluish-white when you are in a cold shadow (in the snow or beside a lake). Being in shadow on sand or dirt doesn't seem bluish because of the reflected light. When sunlight is streaming through the windows of the house but not landing on me, so I'm in the shade, it seems yellowish-white without a trace of blue. We have various "earth tones" on the floors and walls, not blue, so that influences the room light. A sunlight spectrum fluorescent seems bluish, so it doesn't seem like sunlight.

It appears that we want to feel that we are in a warm place, and the sunlight spectrum is making us think we're in a cold shadow. I also suspect that the mismatch between "sunlight spectrum" and real sun has something to do with reflections. A modified sunlight spectrum bulb could add the effect of earth tone reflections into the bulb color.

I tried to do the same thing for myself with some sunlight bulbs in my bedroom and I couldn't stand it.

I often wonder about these types of regulations. I would much rather see a 1$/bulb tax on incandescent bulbs drive people to more efficient solutions when it's reasonable to do so. So, if I want a 150watt light for my attic that is on for 15 hours a year then there is no reason to go with LED's at the same time I am now much better off using an LED for kitchen lighting. Does anyone know why such things are so rarely used?

Because then it would be a tax. Also, we couldn't have the warm fuzzies of having 100% conversion to CFL/LEDs, 99.5% might have the same practical effect, but it doesn't have the same rhetorical force.

I do not know whether to remove only the parentheses, or also the text fragments inside them to get closest to the truth, but I think this changeover is not (only) optimized for the short-term good of consumers. It (also) is optimized for the good of lightbulb producers.

They want a fast transition, so that they can scale up production fast. Regulations that forbid production and/or sale of old-style bulbs make such a scale up easier for them.

Enforcing a fast change also may have a net positive effect when looking at the entire transition period.

Because politicians want power and there is no power in letting people decide for themselves what they want to do.

It isn't going to save me money though, because i am going for the halogen bulbs which save only 30% and then buying those that are a bit more powerful than the bulbs they will replace (ie 40 gets reålaced by a sixty).

Fuck politicians.

I've been as frustrated as anyone with CFL bulbs that die early deaths, but I think this article is more than a little over-the-top with the CFL bashing. None of the CFLs in my house are "horrible, flickery, ugly." Many of them have lasted for years and put out light that's indistinguishable from incandescents.

Still and all, I'm glad to see something even better on the way.

A lot of people seem biased against them from poor early examples. They've gotten a lot better.

The ones I've tried still make a terrible humming noise much like a fluorescent bulb in a ballast, and cast a somewhat pinkish light. They also don't fit well in fixtures designed for incandescent bulbs, sticking out at the end (looking at a bare lightbulb is no fun for the eyes).

I really want to like CFLs but with all of these disadvantages and how much more difficult they are to safely dispose of than a plain incandescent, I still haven't switched.

The form factor (for some applications) is a genuine problem, but it's the only remaining problem in my recent experience. There is a reasonable facsimile of a 60-100W "A" bulb for use with lamp shades that clip onto the bulb, but the base widens too abruptly for some fixtures, and low-wattage bulbs do tend to be longer than their incandescent counterparts.

I'm not using any "name" bulbs (except in photo lighting, which is another kettle of fish entirely) at the moment (they're the cheapies from Canadian Tire) and it has been a long time since I've experienced mechanical noise, flicker or an unacceptable spectrum (there are only a few very small gaps, as revealed by a diffraction spectrometer -- er, a CD held at an angle, which has served me well as a photographer over the years).

And "pinkish" is weird -- it sounds like somebody's tried to use older "conventional" phosphors (which gave a very green-biased spectrum) and tried to overcompensate with the complement (magenta). I've never run into that with any of the brands I've tried (and I'm rather picky).

ADDED: the buzzing shouldn't be a problem with a recent bulb, either. That's an artifact of an older ballast design that I haven't seen used in years. All of the ones I've tried in the last five years or so have had high-frequency ballasts and long-decay phosphors to deal with the flicker issue (it's not an issue anymore), so the 120Hz buzz went away at the same time.

Maybe the humming I hear is due to old lighting fixtures, but I don't want to replace all of them in my apartment :)

I think it's things like this that make mainstream adoption unlikely. And difficulty of safe disposal (but I'm being optimistic, and we might just get tons of mercury in our landfills if people are fine being negligent).

I came to write the same thing. I have only CFLs in my house except for outdoor lights. They work perfectly fine, the light quality is great, they don't die, and except for a terrible model which I got rid of, they all turn on right away. None flicker, and they make a lot of light.

Since we're offering anecdotes, I spent some significant money (considering that we're talking about light bulbs here) to switch over to CFLs a few years ago. It was a disaster. Most lasted less than a year. Two (out of an original 20 or so) are still working.

I'm stockpiling incandescents so I can wait and see if the LED technology proves itself in the real world.

Can you mention the brand of the CFLs? I switched over just about every bulb in my house 4 years ago. For most I got the 100watt ones from Costco, I honestly don't remember the exact brand name it is electralux or something like that. I've replaced one of them. We have about 20 of those conical lights in recessed fixtures, I converted those to the ones from Home Depot. I've replaced 2 of those. The only really noticable thing I've noticed is that they take time to load which I actually sort of like in the early morning, they start a little bit more dim and after about 2 minutes reach maximum brightness. The cone ones have some sort of "yellow light" filter on them so it's not surgical room bright white. There are two lamps with kind of a crappy lampshade that seem maybe un-naturally white and bright but otherwise we've been really happy. I did two outdoor lights and they're working great too, this is in Colorado and they've operated in temperatures from negative 20 to about 100, still seem to work fine after 3 years.

I've heard the horror stories about spending $150 on lightbulbs only to have crappy light and having to replace a bunch of brokens but I haven't had that experience. Not sure if it's a brand issue or dirty power or something else.

I don't argue that early CFL's had big problems, but I'd seriously encourage you to try again.

First, they're quite cheap. Assuming you don't need dimmable CFL's, you can get them for less than $1/bulb. With my utility's incentive programs (Southern California Edison), I often see 60W replacements for ~$0.20/bulb.

Second, they've gotten quite a bit better. Less buzzing, less failure and an overall better quality of light.

Thing is there is no reason to change lightbulb technology the old bulbs worked perfectly.

So when new bulbs are put on the market it isn't unrealistic to expect them to work as least aswell as the ones they are supposed to replace. When they fail to do that, why should we risk even more money just because thay are supposed to be less bad now.

No reason? Only if you don't care about your energy bill.

Running a 60W light bulb for 6-hours a day for a year costs - in California - $18.25. Multiply that by, I donno, 5 bulbs in your house and you're spending $91.25/yr on your lighting.

If you replace those 5 60W bulbs with 13W CFL's, and your cost is just $21.90/yr for the same amount of light. Even including the cost of buying 5 new CFL bulbs, and ignoring the cost of replacing your incandescent lights, you're going to save ~$65 in energy savings just the 1st year.

Which is shit for nothing when you compare it with the cost of gas, rent or (and this particulary irks me: food).

I run only the bulb in the room I am in, which means i would save less than 20$/year which is less than my low care limit.

Add the shit lighting early bulb death and possibility of mercury poisoning my room (you are supposed to leave for half an hour after you drop one, then clean up with heavy gloves) and replacing the bulb goes from an economically decent idea to something less than attractive.

I had a similar experience, but one thing I noticed was the fixture mattered a whole lot because heat shortens the CFL lifespan considerably. The ones that last the longest were the old-style end table lamps (with lampshades) with a single vertical socket and plenty of airflow. The worst are multi-socket horizontal fixtures with no airflow.

The newer bulbs are definitely better, but they still don't last long in the wrong kind of fixture, and if that's the kind of fixture you have you're better off just buying incandescents.

Oh boy, I do love reading an article in Wired about a field I specialize in. It just makes me so amazingly happy.

1.) Wired sure does love yellow light! Kinda odd, since this is a magazine that is, ostensibly, about modern technology; unlike say, Good Old Days.[1] What they smoothly elide is that the sensitivity of the human eye peaks at 555 nanometers. (green)[2]

The more red you have in your white light spectrum, the less efficient the lamp is.

This is a hard physical limit. No amount of cleverness will get around it-- the eye just isn't as sensitive to red light. The warmer the light, the less efficient your bulb will be. 2700K (warm-white) is pretty bad. 5500K (pure white) is okay. 7000K would be ideal, but I don't think anybody actually makes lamps with a color temperature[3] that high.

2.)

  ...Additional colors and increased brightness required more nuanced control 
  of layer composition and depth. Modern LED makers accomplish this by using 
  precise ratios of indium, gallium, aluminum, and nitrogen for the crystal 
  layer, which results in a bluish color.

  But on their own, not even advanced LEDs can produce anything suitable for 
  the living room. The blue-tinged illumination is fine for, say, a pen 
  flashlight on a keychain, but it doesn’t come close to the warm light the 
  human eye desires.

  So the LEDs found in current household applications are blue diodes daubed 
  with a powdered coating called a phosphor, which includes rare-earth 
  elements that filter blue light.

Not wrong so much as massively, massively misleading. Early white LEDs were also phosphor laminated, because LEDs are monochromatic devices. There's no way to get broad-spectrum light out of them otherwise. These phosphors, by the way, are the same coatings that produce the "awful, sickly" light in the CFLs Dan hates so much. LED phosphors run off of blue light, not ultraviolet, but the principle is the same.

---

1: Actual magazine, that actually exists. http://www.goodolddaysmagazine.com/

2: https://secure.wikimedia.org/wikipedia/en/wiki/Luminous_effi...

3: https://secure.wikimedia.org/wikipedia/en/wiki/Color_tempera...

However, their pseudo-scientific mumbo-jumbo about "what the eye desires" aside, Wired is right that people hate non-yellow light.

Hate.

This is a hard psychological limit. No amount of energy efficiency will get around it. If you make LED lighting, it must reproduce the color profile that people are used to from incandescent bulbs.

I think that this is too broad of a generalisation. I personally, and many of my friends as well much prefer whiter light. When I go to the store I buy the bright white CFL's [1] that make the dark go away ... ;-)

I know of many other people, including most of my family that prefer that type of light over the yellow light that incandescence provide. I grew up on CFL's though, my grandpa used to work at Phillips and used to get massive discounts on all of their products.

[1]: http://www.homedepot.com/h_d1/N-5yc1v/R-100686993/h_d2/Produ...

Many comments on HN have said that it's totally the opposite in Asia: people Hate yellow light and like the bluish light you get from cfl:s. So I guess you really can't make statements that broad.

Why are you talking about efficiency? I don't understand. The preference for warm light has nothing to do with efficiency and everything to do with what people like.

Its like you saying "but we can produce this green fabric much more cheaply, why do people like those damn red t-shirts so much?" One is not related to the other.

If you didn't care about power efficiency, then presumably you wouldn't use LED lighting at all. No matter how cheap a LED lamp gets, it's never going to match a piece of wire in a glass bulb.

There is a middle you conveniently excluded. It's possible to care about efficiency but not quite so much as to want green light. As far as I know it is possible to make LED lights with red light which are more efficient than light bulbs.

And besides: In my country I will soon be unable to buy wires in glass bulbs. I and everyone else needs an alternative.

Check out this article The Incandescent Bulbs that Comply with the 'Bulb Ban'

http://www.thedailygreen.com/environmental-news/blogs/republ...

The demo as described is kind of silly… it's easy to get two bulbs to appear to generate the same color white light reflecting off a given background; there are at most 4-5 variables to adjust (given that humans have 4-5 different classes of light sensors). A group of 5 LEDs (red, yellow, green, aqua, blue) could be made to pass this test but would render colors terribly.

Color me impressed when participants can't tell the difference between rainbows generated by each light passing through a prism – that would be a much better test of color rendering ability.

To test the color rendering ability just take a CD or a DVD disc, and hold it to the light. On CFLs you'll often see just a few streaks instead of a rainbow, while halogen lamps and LEDs are pretty good.

Thanks, that's a good tip. I'm surprised that all my CFLs (even ones with supposedly good CRI) show up as red, green, and blue blotches...

Ever since I heard about "dirty energy" emitted from CFL bulbs, I've become wary of fluorescent bulbs and pro-LCD bulbs. Especially because I'm an asthmatic: http://www.youtube.com/watch?v=VS5ogZxoZ2Y http://www.magdahavas.com/2009/12/05/gs-units-explained/

Can anyone with more knowledge on the subject verify if the dirty energy info about CFL bulbs is true, and if LCD bulbs will be free from that?

I really wouldn’t worry about “dirty energy”. There is likely no effect at all, any effects you might perceive are probably psychosomatic.

Here is a study looking into health effects of electromagnetic fields: http://www.nap.edu/catalog.php?record_id=5155

Here is another study looking at people suffering from electromagnetic sensitivity: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=S...

And another one: http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=S...

I hope not. I spend a fortune on an led bulb a half or so year ago.

Not only was the light so bad my desk looked like the inside of a morque, but as the sun went down I discovered that the light it did send out was so weak that I could't see anything.

One expensive lesson later and I am not going to be using anything like an led again.

I had planed to stay with the good old fashioned lightbulb (I can afford the bill) but the ever meddlesome lawmakers made those illegal to import.

I'm not really that 'light' savvy but this seems good. It's like the transition from horses to automobiles.

In countries or areas with a cold climate the argument of energy conversion is less significant as most of the energy consumption is used for heat anyway.

To those advocating that LED bulbs will last longer, you might find this interesting: http://en.wikipedia.org/wiki/Phoebus_cartel

Less, maybe. But no place is cold for the entire year, the heat is generated in poor places (for example if you have cans all the heat is generated above the insulation, which is pointless). And electric heat is much less efficient than natural gas.

  And electric heat is much less efficient than natural gas.

Less efficient per dollar, depending on the cost of electricity and natural gas. Electric heat is, of course, 100% thermodynamically "efficient", since all the power eventually ends up as heat. With natural gas, you have to pipe the exhaust outside, and you lose a small amount of heat that way.

Is there a reason you are ignoring transmission and generation losses?

By your standard natural gas is also 100% thermodynamically efficient - all of it ends up as heat. Some of it outdoors, sure, but that is true for electric heat as well. Those thin electric lines outside your house get pretty hot.

Is there a reason you are ignoring transmission and generation losses for natural gas? Methane isn't a frictionless fluid, it costs real money to pump it through pipelines. And, of course, you have to dig it out of the ground in the first place.

> And electric heat is much less efficient than natural gas

Not this argument again. Keep in mind that not everyone has natural gas heating. In my part of the country (Pacific Northwest), many homes are electric heat only. So during the winter time it's a zero sum game.

"during the winter time" being the operative word. Deep cold in winter is about 3 month, and few more months of lesser heat.

But the light bulbs are used the entire year. Plus the light bulb is positioned suboptimally for heating - usually in the ceiling, or even worse in cans.

And people use A/C in the summer, so add about 1/3 to the energy waste.

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