ultra-efficient incan, 173 Lm/W

[sambob223]

A photon-recycling incandescent lighting device

Well, guess what's coming?

Yeah..pretty sure not In my life time .
Still waiting for ink jet printed video displays I heard about back in early 2000, supposed to replace billboards...still waiting it was only 5-10yrs away back then.
Still sounds really cool though.

 

[chillinn]

The problem is that incandescent has too much red in it.

How and why is that a problem.

Ideally, a light which can mimic sunlight exactly would be the ideal light source.

This is an opinion which I disagree with, or at least see it as a generalization that only holds true after sundown for a few hours at most. You do not want 5000K sunlight at midnight or 4AM, you'd want more and more warmer temperatured light as the night goes on, and the warmest just before sunrise.

Yes, but as mentioned the higher the CRI, the smaller the blue spike. I hope you know sunlight has a copious amount of UV in it. LEDs have none. UV is far more damaging than blue light.

I see this claimed quite a bit, yet I see no evidence of this. Citation needed. Also, anyone that has owned a High CRI LED for any length of time will tell you it fades, so even if the blue spike is smaller, which I doubt, it comes back within dozens of hours of use. And what I suspect is the issue is not that these elements are present in sunlight, but that the spectrum profile of sunlight is a flat curve, not a spikey one, There's as much UV in sunlight as there is any other color, more or less. Because all LED are blue LED, there is always more blue than any other color.

It seems from that study that general lighting isn't the primary cause of the increase in macular degeneration. Rather, it's the much higher levels of blue light we get from the screens we stare at all day long.

I wonder how screen backlights are different from the LED in a flashlight or LED in general lighting.

Again, that's primarily due to screens on the devices we insist on using, not due to general lighting which is far lower in intensity.

But not entirely, but we won't worry about the fact that this could be because compared to flashlights, the vast majority of LEDs are in screen backlights, which would explain the "mostly," but, you know, an LED is an LED is an LED.

I'd say diet and lack of exercise are much more highly correlated with diabetes and heart disease. While on the subject of disrupting circadian rhythms, why no outcry about the significant percentage of the population (i.e. night people) who are forced to fight their circadian rhythms because day people dictate the schedules the world runs on? While we're at it, two things have made this even worse over the last few decades. One is earlier school/work start times. 9 AM used to be standard for both, and even that's too early for many night people. Now I've heard of some schools opening as early as 7 AM. The other thing is daylight saving time. That pushes everything back yet another hour. The biggest stupidity is the idea to make DST permanent. I'm all for not changing the clocks anymore, but it should be permanent standard time.

Just because diet and lack of exercise may be the cause of more incident of diabetes and heart disease does not diminish the risk of same from LED lighting. Same for all your other examples. These are straw man arguments.

PWM isn't inherent to LEDs.

Funny, though, that 99.99% of all LED drivers employ PWM, and finding a CC circuit is like finding a needle in a haystack.

Yeah..pretty sure not In my life time .

I misspoke. They built one, so it is technically here already, i.e. the science is not just compelling, it is now very well proven. And if it only took 7 years from MIT's proof of concept to this group publishing earlier this year the accomplishment, it's just a matter of a few years optimizing manufacturing processes and accumulating investors before it can get to market. One can only hope it can be developed and miniaturized for portable handheld lighting also, so we don't have to suffer with inefficient and optically inferior LED flashlights anymore.

 

[jtr1962]

How and why is that a problem.

Because it results in low CCT and yellowish lighting which some people hate.

This is an opinion which I disagree with, or at least see it as a generalization that only holds true after sundown for a few hours at most. You do not want 5000K sunlight at midnight or 4AM, you'd want more and more warmer temperatured light as the night goes on, and the warmest just before sunrise.

Asthetic preference, and in some cases where you're task lighting, higher CCT enables better contrast and visual acuity (important for streetlighting especially).

I see this claimed quite a bit, yet I see no evidence of this. Citation needed.

Go look at the spectrum of LEDs. For example, see this. Look at the comparison of the spectrum with "regular" CRI 80 LEDs.

Also, anyone that has owned a High CRI LED for any length of time will tell you it fades, so even if the blue spike is smaller, which I doubt, it comes back within dozens of hours of use. And what I suspect is the issue is not that these elements are present in sunlight, but that the spectrum profile of sunlight is a flat curve, not a spikey one, There's as much UV in sunlight as there is any other color, more or less. Because all LED are blue LED, there is always more blue than any other color.

Sorry, but this is a blatant falsehood. I've never heard of high CRI LEDs "fading" after a few dozen hours. That would mean a pronounced color shift towards royal blue if a blue hump suddenly became a blue spike. Color stability over time is thoroughly tested by all LED manufacturers.

The issue, to the extent that it's even an issue, is that LEDs contain too much blue light around 450 nm, and not enough from maybe 470 nm to 520 nm (i.e. the cyan "valley"). This is one reason why LEDs with this type of spectrum only have a CRI of 70 or 80. You need to fill in the valley to get to CRI 90, and especially CRI 95+. So high CRI LEDs mostly fix the problem, although they don't quite match up to a blackbody radiator.

UV is harmful regardless of whether it's spiky or not. It's far more harmful at any given intensity than the 450 nm spike in LEDs.

I wonder how screen backlights are different from the LED in a flashlight or LED in general lighting.

They're filtered by the LCD screen to give whatever color the pixels need to be. Some colors then have very little blue content.

But not entirely, but we won't worry about the fact that this could be because compared to flashlights, the vast majority of LEDs are in screen backlights, which would explain the "mostly," but, you know, an LED is an LED is an LED.

It's intensity and time of exposure which matters. In general, the intensity of a screen at the distance it's viewed is far higher than indoor general lighting, and even higher than outdoor lighting like streetlights. And yet I read all this panic about the blue spike in LED streetlights which most people are exposed to for minutes at most, but virtually nothing about the screens we use for hours.

Just because diet and lack of exercise may be the cause of more incident of diabetes and heart disease does not diminish the risk of same from LED lighting. Same for all your other examples. These are straw man arguments.

The point here is the risk from LEDs is far lower than the other factors given typical toxic American lifestyles. If everyone led a perfectly healthy life, ate good food, never got fat, exercised, etc. then disruptions to circadian rhythm due to artificial lighting might be a primary health risk. Even then, that doesn't mean it would necessarily pose a large risk. Rather, it would simply pose a larger risk than anything else. A good analogy might be to compare the present American lifestyle to cutting yourself with a large knife. LEDs might be the equivalent of a paper cut. Change everything else (i.e get rid of the large knife), and LEDs become the primary health risk, but they're still a paper cut.

If we're really worried about disrupting Circadian rhythms, the low-hanging fruit is to make schedules which better accommodate night people, not to get rid of LEDs.

Funny, though, that 99.99% of all LED drivers employ PWM, and finding a CC circuit is like finding a needle in a haystack.

Not for general lighting. Flashlights use it for cost/simplicity/space reasons. Non-dimmable LED general lighting is almost always constant current, although the cheaper versions let through some 120 Hz flicker. Dimmable LED lighting can use either PWM or current regulation. There's not much cost difference between them because there needs to be a constant current circuit regardless with general lighting. Not always so with flashlights where the power supply might be closely matched to the LED voltage. Flashlights might just use a resistor to limit current at maximum intensity, then use PWM to get dimming.

I misspoke. They built one, so it is technically here already, i.e. the science is not just compelling, it is proven. It's just a matter of optimizing manufacturing processes and accumulating investors before it can get to market. One can only hope it can be developed and miniaturized for portable handheld lighting also, so we don't have to suffer with inefficient and optically inferior LED flashlights anymore.

Yes, the science is proven and it works. We got working fuel cells in the 1960s but they're still not practical for anything but niche uses. Don't get me wrong, if we can make this cheaply, not need a driver, and also tune the spectrum so you can get any CCT you want without a blue spike I'll gladly welcome it. I'm just dubious we'll ever get to that point. We're chasing after a moving target with LEDs. It might be that there just isn't enough of a potential market to justify any further R&D.

 

[Olumin]

I think we are steering a little off course here with the Ican vs led debate.

Trust me I would be among the first to adopt this technology if it ever becomes available. I mentioned before that I still use mostly halogen lighting in my home & still regularly use incandescent flashlights in & around home. I just no longer carry them because of the short battery life & the potential of a blown bulb when I need it the most. If this technology solves that, count me in.

 

[chillinn]

Because it results in low CCT and yellowish lighting which some people hate.

Is that hatred slowly killing them? Is there any health issue with "low" CCT of 3200K?

and in some cases where you're task lighting, higher CCT enables better contrast and visual acuity (important for streetlighting especially).

It is pretty much the general consensus that more can be seen with less light that has more accurate color rendition than with more light with less, and the higher the CCT, the worse the color rendition. Are there any 6500K High CRI LEDs?

Go look at the spectrum of LEDs. For example, see this. Look at the comparison of the spectrum with "regular" CRI 80 LEDs.

Looks like they reduced the spike, but also moved it to a lower wavelength. Though at first glance the spectrum looks flat, there's still a slight peak in the blue or UV that is higher than the rest of the curve.

Sorry, but this is a blatant falsehood. I've never heard of high CRI LEDs "fading" after a few dozen hours. That would mean a pronounced color shift towards royal blue if a blue hump suddenly became a blue spike. Color stability over time is thoroughly tested by all LED manufacturers.

Phosphor fading a pretty well known phenomenon that has not yet been solved, though I suppose it is generally referred to as color stability. The tint mafia talks about it all the time. The fading begins immediately.

UV is harmful regardless of whether it's spiky or not. It's far more harmful at any given intensity than the 450 nm spike in LEDs.

This is a straw man argument.

The point here is the risk from LEDs is far lower than the other factors given typical toxic American lifestyles.

The point here is the risk from LEDs is far lower than the other factors given typical toxic American lifestyles.

More straw man. Bombs are very dangerous, but this has no effect on the carcinogenic effects of strychnine.

If we're really worried about disrupting Circadian rhythms, the low-hanging fruit is to make schedules which better accommodate night people, not to get rid of LEDs.

Eliminating LED would solve the issue where scheduling may not. But my argument is not, "get rid of LED because of these problems," it's "make something better than LED because of these problems." Getting rid of LED is incidental.

Not for general lighting. Flashlights use it for cost/simplicity/space reasons. Non-dimmable LED general lighting is almost always constant current,

And dimmable?

We're chasing after a moving target with LEDs.

But it's moving slower and slower, and the slowdown began around 2015. Most of the exciting advances in LED seem to be towards better and better emulation of incan light source spectrums, not in leaps and bounds increases in efficiency, at least not practically. The improvement in this year's new revision of some model flashlight is marginally if at all better than the model from two years ago.

I think we are steering a little off course here with the Ican vs led debate.

Agreed, though the news release may have made it worth revisiting, we may have had a dead horse the whole time.

LED remains neat, but only after being immersed in LED for half a decade does the contrast with incan make me debate. If LED ever perfectly emulates incan, I don't think there will be any more arguments, at least not from me.

 

[desert.snake]

It is pretty much the general consensus that more can be seen with less light that has more accurate color rendition than with more light with less, and the higher the CCT, the worse the color rendition. Are there any 6500K High CRI LEDs?

Lol, for a few years now, maybe more. I have JetBeam Jet-U with Nichia Optisolis 6500K and 98CRI
like this

LumiBar-52-3098+ Nichia LED Strip Optisolis CRI99 D65 cold white 6500K 28PPF 1480lm 350mA 37.5V 52 LEDs 56cm module (2643lm/m 24W/m)

Optisolis™ technology from Nichia marks an important milestone in the industry, offering a natural light spectrum that contributes to our well-being, helps us to be more productive and has a major importance in all areas where correct color appreciation is important. Highly realistic color...

www.lumistrips.com

It illuminates everything around like a winter morning


Also E21a

[Mod] Olight H2R with Nichia E21A LED 6500K R9080

Translate via Google Olight H2R is a very practical high brightness headlight Using optical lens Use a small electric drill to carefully drill 2 holes, and do not hurt the lines inside Then use a knife to clear out the space under the pressure ring Use the lever principle to open...

budgetlightforum.com

 

[Olumin]

I think most people would be very hard pressed to tell the difference between a 3400k 95+ CRI LED & a xenon or halogen bulb. I often can barely tell myself. Reality is most people just dont care about CCT or CRI very much, or simply dont notice the difference. LED will never be able to perfectly emulate a hot wire, but that was hardly the goal. Im sure some people (not most, lol!) complained just as much when electric light bulbs displaced town gas lighting. Its like comparing an electric heater with a wood stove. A fire is pleasant, atmospheric & probably better for your mental health, but I wouldn't wanna light my home with it anymore.

 

[chillinn]

It illuminates everything around like a winter morning

Thx for posting. What makes those winter mornings so special is that they are novel, that we don't see them every day. I just think it's a little something that so many prefer the light of overcast skies to blue skies. But some cool white I have appreciated, such as Fenix's cool white from a few years ago (I just haven't seen anything recently to know).

I think most people would be very hard pressed to tell the difference between a 3400k 95+ CRI LED & a xenon or halogen bulb.

The narrow color band makes it obvious to me. Halogen doesn't produce precisely 3400K or whatever, that's just where it peaks.

Reality is most people just dont care about CCT or CRI very much, or simply dont notice the difference.

But what most people care about doesn't change reality, and that is not to say what they don't care about won't hurt them, either.

LED will never be able to perfectly emulate a hot wire, but that was hardly the goal.

I'm not so sure on both accounts; I'm mildly optimistic in the former, and at odds with the latter.

 

[Olumin]

[...] and that is not to say what they don't care about won't hurt them, either.

But they really dont. Im sure we all do some things that we know are bad for us. Whether we smoke, drink sodas or eat more sweets/snacks then we should, spend hours in front of screens, live in cities with bad air quality, drink out of plastic bottles, have unhealthy hobbies or jobs etc. Most people just dont care enough to do something about it. Unless the negative effects of something are both immediate & acute, aswell as guaranteed, most people will just carry on as usual. Reality is life is a lottery & whether you drink, smoke, dont work out or dont eat well, chances are something else will kill you before that ever becomes an issue. Thats how most see it anyway, even if not consciously.

 

[chillinn]

Aside from the hasty generalization of "no one," (as surely it can't be absolutely no one, health nuts for instance), the things that hurt everyone whether they care or not (like leaded gasoline) should be discovered, acknowledged, mitigated and/or reduced, as per the 1972 Consumer Product Safety Act, which directs the US Consumer Product Safety Commission to "protect the public against unreasonable risks of injuries and deaths associated with consumer products." It's not an individual choice here, it's one of those higher order mandates we agree to abide by in exchange for the liberties and privileges granted by citizenship, to the benefit of everyone, which benefits the country, as a country can't function properly if large swaths of its membership are being picked off by lawn darts.

 

[Olumin]

But I didn't write "no one", I said "most", which I believe is accurate. Leaded gasoline has been (largely) outlawed, so has radioactive makeup and lead paint on dinner plates. however, none of the examples I listed are outlawed and there are thousands more that arent. They are very much still a personal choice, and for most of them, I doubt that will ever change. You cant protect people against every source of potential danger, unless you place them in a padded cell & strip them of all their freedoms of cause. You can educate them, but you cant force them to listen (not in free country anyway). The potential dangers of LED lighting are not severe enough to rationalize a ban on them, just like it isnt illegal to put too much sugar in your coffee.

 

[Olumin]

Now that I think about it, they bann ninja stars & nun chucks in some countries. So who knows, you might get your LED ban after all. I forgot that modern law making isnt necessarily based on logic or reason, lol!

 

[chillinn]

When it comes to product safety, the democratic process is so abstracted it's not as though there's any individual say in the matter. I don't want to ban LED (though I would ban PWM LED drivers in a heart beat), and it's not as though LED overtaking the lighting market banned incan (though I think maybe there is a ban on the most inefficient incan?). It is only my taste that tells me incan provides more atmosphere, and the other reasons are merely my poor attempt at persuasion and overreaction to what I see as LED bias. Maybe high efficient incan will mature, and I won't like it, and want to stick with low efficient incan, I can't say for sure. But I sure do want to see what it's like and not dismiss it wholesale because I'm happy with LED, because I'm really not, obviously.

 

[jtr1962]

Is that hatred slowly killing them? Is there any health issue with "low" CCT of 3200K?

According to you, if the 3200K happens to be LED then there's a health issue due to the blue spike.

As others have mentioned, compared to other things, the blue spike in LEDs represents at best a minor health risk. Should we attempt to reduce in the future? Absolutely because by doing so we also arrive at the desirable result of increasing CRI. Plus it won't add significantly to the cost of LEDs. There's no downside to reducing the spike, and lots of potential upsides.

Looks like they reduced the spike, but also moved it to a lower wavelength. Though at first glance the spectrum looks flat, there's still a slight peak in the blue or UV that is higher than the rest of the curve.

Sure, it's not perfect, but at some point it no longer has the issues a huge spike at 450 nm does.

Phosphor fading a pretty well known phenomenon that has not yet been solved, though I suppose it is generally referred to as color stability. The tint mafia talks about it all the time. The fading begins immediately.

From your link it appears other light sources have even less chromatic stability than LED. Also, that paper is dated in 2017. To a first approximation chromatic shift in LEDs is caused by heat first, then current density. As LEDs become more efficient, heat is less and less an issue. In the 6 years since that paper was written, there have been huge improvements in LED color stability, to the point it's largely a non-issue nowadays.

Eliminating LED would solve the issue where scheduling may not. But my argument is not, "get rid of LED because of these problems," it's "make something better than LED because of these problems." Getting rid of LED is incidental.

As a night person I can tell you being up when my body tells me I should be sleeping is the problem, not the light source I use. Since I'm a night person, I do most of my sleep when the sun is up. So yes, scheduling so night people can sleep when their body tells them to would largely fix the problem.

And dimmable?

Most of the ICs used in dimmable LED general lighting use constant current dimming. You need the constant current circuit anyway. It's almost trivial to vary that current depending upon the setting of the lamp dimmer. The bad designs still let 120 Hz flicker through but that's easily fixed by having enough filter capacitance.

But it's moving slower and slower, and the slowdown began around 2015. Most of the exciting advances in LED seem to be towards better and better emulation of incan light source spectrums, not in leaps and bounds increases in efficiency, at least not practically. The improvement in this year's new revision of some model flashlight is marginally if at all better than the model from two years ago.

The big story for the last 5 years isn't huge improvements in efficiency. Rather, it's the huge drop in cost. I remember when power LEDs putting out perhaps 100 lumens cost $25. Now you can get mid-power LEDs which put out the same amount of light at 1/5 the power, and cost a cent each in large quantities. We've also gotten much better at color consistency. There's no longer a tint lottery like there used to be. And high CRI LEDs which emulate a black body better are now readily available in all color temperatures. We'll continue to improve in all these areas, even if efficiency only continues to improve very slowly.

LED remains neat, but only after being immersed in LED for half a decade does the contrast with incan make me debate. If LED ever perfectly emulates incan, I don't think there will be any more arguments, at least not from me.

For a lot of people your last sentence is already true. LED emulates incan with enough fidelity that they just don't notice or care about the remaining differences. My brother never bought CFLs because he hated their color. He stuck to using incandescent. After LEDs were out a few years he tried them and never looked back. They were close enough to incans that he didn't care, plus the energy savings made it worthwhile.

 

[chillinn]

Just FYI, rather than acknowledging them, you are systematically rationalizing away every single valid criticism of LED.

As a night person I can tell you being up when my body tells me I should be sleeping is the problem, not the light source I use

Because dawn is a flood of blue and UV light, and we and our eyes evolved under the sun, a blue light at night resets circadian rhythms such that the body now "thinks" it is dawn.

Most of the ICs used in dimmable LED general lighting use constant current dimming.

Amazing that the most of the non-dimmable LED lighting uses constant current, and most of the dimmable LED lighting uses constant current, and yet I can't seem to get away from PWM. I'm like Charlie Brown with a rain cloud following me around when everyone else gets to enjoy a nice day. Weird. OK, if you say so, but I detect PWM literally everywhere, so regardless of PWM rare in general lighting, consumers seem to be attracted to it for some reason.

LED emulates incan with enough fidelity that they just don't notice or care about the remaining differences.

Bandwagon arguments are not persuasive.

 

[jtr1962]

Just FYI, rather than acknowledging them, you are systematically rationalizing away every single valid criticism of LED.

Because most of them are nitpicking. This isn't like lead in gasoline where most people will agree that it's extremely harmful and needed to be banned. The blue spike doesn't affect everyone equally, and even worst case is a minor issue. The larger issue is people exposing themselves to light before they need to sleep. Doesn't matter what kind of light, either. Some people have trouble sleeping after being exposed to light at night. I don't happen to have that problem.

Because dawn is a flood of blue and UV light, and we and our eyes evolved under the sun, a blue light at night resets circadian rhythms such that the body now "thinks" it is dawn.

That's typical day person thinking. For night people that same flood of light at dawn tells them to either stay in bed, or go to bed. The solution for people who have this problem is very easy. Just avoid light at times when it interferes with sleep.

Amazing that the most of the non-dimmable LED lighting uses constant current, and most of the dimmable LED lighting uses constant current, and yet I can't seem to get away from PWM. I'm like Charlie Brown with a rain cloud following me around when everyone else gets to enjoy a nice day. Weird. OK, if you say so, but I detect PWM literally everywhere, so regardless of PWM rare in general lighting, consumers seem to be attracted to it for some reason.

Are you sure it's not 120 Hz flicker, which is undetectable to most people, yet it causes problems? Lots of cheaper LED general lighting has this 120 Hz flicker problem, even using constant current drivers. If the filter capacitance is too small, the current will drop, perhaps all the way to zero, 120 times per second.

Bandwagon arguments are not persuasive.

Neither are using arguments to rationalize not using a light source you happen to dislike, even though by most metrics that light source is better than anything else out there at this time. There's a reason LEDs have taken over lighting. If there was some horrible downside don't you think it would have surfaced by now? There are some minor issues, like the blue spike, to which solutions exist. And of course the CRI is less than 100, but for most lighting uses it doesn't need to be 100. Note that the CRI is 96 for the new tech incandescent this thread is about. Would you nitpick about that also to justify continued use of old school "regular" incandescent?

For most people, they don't care if a replacement is better in every way. It just needs to be better in the ways that matter. LEDs win hands down in terms of efficiency and now cost, while they're "good enough" in the other metrics that most people just don't care. It's becoming sort of the same with EVs starting to become mainstream. They win hands down in terms of maintenance, TCO, simplicity, etc. Their downside is they can't be "refueled" as quickly as ICEs, but that's moot so long as the range is high enough for the majority of trips people will use them for. LEDs have a few downsides also, but none of them are major showstoppers or they wouldn't have penetrated this far into the lighting market.

 

[bykfixer]

In all my years on planet earth I've only had 2 LED's go . One was when I threw 8 volts at a Maglite ML25 3 volt driver The other was a really rare 3 volt vital gear drop in module I did not realize was a 3 volt drop in module and I threw 6 volts at it. It glowed a nice bright blue a few seconds and faded to nothing soon after.

Bulbs? That's a different matter. Some bulbs are tougher than others but in the end they all go a lot faster than a normal driven LED.

Is there an inherent danger to using LED's? Don't know, don't care. I work 6" from traffic, drive 10's of thousands of miles on the interstate yearly, have eaten my weight in fast food over the years, survived numerous automobile crashes, grew up with lead paint and leaded gasoline, drank from the garden hose, swam in creeks, rode bicycles brakeless, surfed not far from sharks, peeved off a few people to the point they drew a gun, still eat fast food, drink from plastic bottles, spray roundup on my yard, etc etc.

Just getting out of bed can be a gamble. One lego piece in the wrong place and WHAM-O, head butt to the bathroom sink. The other night I stepped out of my truck onto a sandy pavement but because I have a rule of always having two points of grip did not fall. Yet that could have led to a deadly concusion. So if my LED Maglite puts out harmful rays, it's no concern to me. The car with a stoned driver that wizzed past at 45mph is....

I'd love to see those MIT bulbs come to fruition. But I aint holding my breath.

 

[chillinn]

Because most of them are nitpicking.

These are not nitpicks:

• https://nymag.com/strategist/article/led-light-bulbs-investigation.html
• https://www.greenmatters.com/news/led-light-health-risks
• https://www.downtoearth.org.in/news...ul-scientists-suggest-a-simple-solution-58544
• https://www.cnn.com/2019/05/16/health/blue-light-led-health-effects-bn-trnd/index.html
• https://www.theguardian.com/environ...ighting-risks-harming-human-and-animal-health

But that is more handwaving and rationalizing away legitimate problems and concerns.

Some people have trouble sleeping after being exposed to light at night. I don't happen to have that problem.

Circadian rhythms are most usually a 24 hour cycle that tells you when to sleep. Regardless of not being conscious of it, you have a circadian rhythm which affects your sleep, eating, core body temperature, brain wave activity, hormone production, cell regeneration, and other biological activities. If you were not subject to circadian rhythm, you would simply be dead or dying. If you're an evening person, some research suggests that your body clock runs slower than 24 hours. You'll find it hard to wake up in the mornings and feel alert. You'll have the most energy much later in the day, like 11 p.m. But you most certainly are affected by circadian rhythms and blue light. And lifestyle is a choice, you were not born a night person, you decided upon that lifestyle, and as it happens, your choice of being active during the night and inactive during the day will result in a shortened lifetime compared to those who wake with and retire with the sun, so no wonder you don't care about the documented poor health effects of LED light.

That's typical day person thinking. For night people that same flood of light at dawn tells them to either stay in bed, or go to bed.

This is an arbitrary distinction that only exists because of your choice of lifestyle. IOW, the distinction between "night people" and "day people" is an illusion.

Are you sure it's not 120 Hz flicker, which is undetectable to most people, yet it causes problems?

Is that what I see in brake lights and dash lights, and outdoor lighting? Back when TV was tubed and 60Hz, it never bothered me. Turning a dimmer switch down on dimmable incan chandeliers so far that the flicker could be seen never bothered me. I use Lightsaver Miser tailcaps on incans sometimes, which utilize PWM for half and quarter brightness, and that doesn't bother me. The first generation of the Zebralight SC5w didn't utilize PWM strictly speaking, because the brightness cycle never dimmed to zero, yet migraines occurred within a half hour of use. I had to give it away. The Mk II second generation didn't cause migraines, though it used the same PWM-like scheme of dipping brightness for longer runtime. Surely, there must be some LED PWM drivers that don't bother me, but it seems to have nothing to do with the speed of the frequency. Natural brain frequencies are denoted as alpha: 8-13 Hz; beta, 18-25; theta: 3.5-7 Hz; delta: 0.5-3.5 Hz, and gamma: 30-70 Hz and I suspect it has something to do with whether a particular implementation of PWM is a harmonic or multiple of some brain frequency, though I can't say for certain. But pain caused by some PWM is a motivator to avoid all PWM and wish and pray that it stops being used, because it is unnecessary and constant current circuits are more efficient.

Neither are using arguments to rationalize not using a light source you happen to dislike, even though by most metrics that light source is better than anything else out there at this time.

I'm not rationalizing anything. I have listed facts, such as an LED of a particular color temperature emitting such in a narrow band, or that blue light resets the body's clock.

If there was some horrible downside don't you think it would have surfaced by now?

See links above, because they have surfaced.

And of course the CRI is less than 100, but for most lighting uses it doesn't need to be 100. Note that the CRI is 96 for the new tech incandescent this thread is about. Would you nitpick about that also to justify continued use of old school "regular" incandescent?

Did I complain about High CRI LED not rendering color absolutely perfectly? I have to admit, though, it is strange that the new incan is not 100 CRI, as all other burning wire I've ever heard of is, and so is candlelight and firelight.

For most people, they don't care

Bandwagon and sweeping generalization. You want to place sentiment above merit and are apparently clairvoyant. I, for one, am envious.

Don't know, don't care.

This is, no offense, hypocritical. Surely there are things you care about, such as not having rat feces in your food. If there is anything you care about, then it is far more likely that you are able to empathize with others that do care.

I'd love to see those MIT bulbs come to fruition. But I aint holding my breath.

To be accurate, a group at MIT had a proof of concept in 2016 ( https://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111 and
https://www.nature.com/articles/nnano.2015.309 ), and though it is a good bet that led to the recent paper and accomplishment, the new story is an entirely different group unrelated to MIT.

 

[jtr1962]

These are not nitpicks:

• https://nymag.com/strategist/article/led-light-bulbs-investigation.html
• https://www.greenmatters.com/news/led-light-health-risks
• https://www.downtoearth.org.in/news...ul-scientists-suggest-a-simple-solution-58544
• https://www.cnn.com/2019/05/16/health/blue-light-led-health-effects-bn-trnd/index.html
• https://www.theguardian.com/environ...ighting-risks-harming-human-and-animal-health

But that is more handwaving and rationalizing away legitimate problems and concerns.

But the solution is slightly different designs for LEDs would remove most of the spike and/or shift it towards less harmful 470 nm. It's not to stop using LEDs and return to an obsolete technology.

Circadian rhythms are most usually a 24 hour cycle that tells you when to sleep. Regardless of not being conscious of it, you have a circadian rhythm which affects your sleep, eating, core body temperature, brain wave activity, hormone production, cell regeneration, and other biological activities. If you were not subject to circadian rhythm, you would simply be dead or dying. If you're an evening person, some research suggests that your body clock runs slower than 24 hours. You'll find it hard to wake up in the mornings and feel alert. You'll have the most energy much later in the day, like 11 p.m. But you most certainly are affected by circadian rhythms and blue light. And lifestyle is a choice, you were not born a night person, you decided upon that lifestyle, and as it happens, your choice of being active during the night and inactive during the day will result in a shortened lifetime compared to those who wake with and retire with the sun, so no wonder you don't care about the documented poor health effects of LED light.


This is an arbitrary distinction that only exists because of your choice of lifestyle. IOW, the distinction between "night people" and "day people" is an illusion.

Where do you get this stuff? Being a night person isn't a "choice" any more than being a day person is. Tell me then why I could never adjust to a day schedule, no matter how much sleep I got? It just never felt right to me, even in grade school when I certainly didn't have the ability to choose to be on a late schedule. If I was ever going to adjust to a day schedule, don't you think it would have happened after 12 years of school?

Here, read up and learn something:

If you’re just not a morning person, science says you may never be

Morning people and night owls are born that way. It's time we accepted that.

www.vox.com

I really, really can't stand the prejudice society has towards night people.

Night people don't have shorter lifespans either unless they're forced to a day schedule which chronically deprives them of sleep. Then again, day people also die younger if they don't get enough sleep.

Is that what I see in brake lights and dash lights, and outdoor lighting? Back when TV was tubed and 60Hz, it never bothered me. Turning a dimmer switch down on dimmable incan chandeliers so far that the flicker could be seen never bothered me. I use Lightsaver Miser tailcaps o incans sometimes, which utilize PWM for half and quarter brightness, and that doesn't bother me. The first generation of the Zebralight SC5w didn't utilize PWM strictly speaking, because the brightness cycle never dimmed to zero, yet migraines occurred within a half hour of use. I had to give it away. The Mk II second generation didn't cause migraines, though it used the same PWM-like scheme of dipping brightness for longer runtime. Surely, there must be some LED PWM drivers that don't bother me, but it seems to have nothing to do with the speed of the frequency. Natural brain frequencies are denoted as alpha: 8-13 Hz; beta, 18-25; theta: 3.5-7 Hz; delta: 0.5-3.5 Hz, and gamma: 30-70 Hz and I suspect it has something to do with whether a particular implementation of PWM is a harmonic or multiple of some brain frequency, though I can't say for certain. But pain caused by some PWM is a motivator to avoid all PWM and wish and pray that it stops being used, because it is unnecessary and constant current circuits are more efficient.

There's good PWM and bad PWM. Good PWM uses frequencies well into the kHz range, which is beyond the ability of your body to be affected by it. In fact, another reason we might use such high frequencies is to avoid banding when people take pictures.

There might be othert factors also. Incan on a dimmer doesn't go completely to zero output because of the thermal inertia of the filament. LED does. Maybe it's a combination of PWM frequency and dropping light output all the way to zero which affects you?

As for using PWM on any type of car lighting, that should be regulated so only kHz frequencies are used. I've seen brake lights myself which pulse at such low frequencies a strobing effect is visible. As for outdoor lighting, like everything else there's good and bad. Good outdoor lighting has no 120 Hz flicker. If it's dimmed via PWM, then only kHz frequencies are used.

Yes, constant current dimming is always going to be more efficient, and I agree that it should be used instead of PWM. The only potential downside is a slight color shift as current decreases, whereas with PWM you get no color shift. To me that's a more than acceptable tradeoff.

I'm not rationalizing anything. I have listed facts, such as an LED of a particular color temperature emitting such in a narrow band, or that blue light resets the body's clock.

See links above, because they have surfaced.

Yes, but as mentioned there are ready solutions. The best one is going with high CRI LEDs. That nicely fixes the blue spike problem in streetlights the AMA mentions without impacting the ability to see. In fact, high CRI improves the ability to see, regardless of color temperature. It's a far better solution than going with 2700K streetlighting as they recommend. Their solution compromises contrast and peripheral vision unless you increase the intensity of the 2700K lighting to compensate. At that point you're back to the same, or even higher, blue light exposure as the 5000K streetlights, while also using a lot more energy. If you don't increase intensity, then you just made things more dangerous. Using 5000K high CRI streetlights reduces the blue light while not compromising seeing. Note here that it's blue light over an entire range which helps peripheral vision and contrast. That means you can get rid of that 450 nm spike without hurting the ability to see, but you still need a certain amount of blue light in the spectrum. You just don't get enough if you drop to 2700K.

Did I complain about High CRI LED not rendering color absolutely perfectly?

Not directly but you mentioned the spectrum doesn't exactly match sunlight. As far as I know, no manmade light source besides maybe xenon arc lights is a perfect match for sunlight.

This is, no offense, hypocritical. Surely there are things you care about, such as not having rat feces in your food. If there is anything you care about, then it is far more likely that you are able to empathize with others that do care.

I care about stuff highly likely to shorten my life, like air pollution or processed junk foods. I can limit my exposure to both, but not completely eliminate it.

To be accurate, a group at MIT had a proof of concept in 2016 ( https://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111 and
https://www.nature.com/articles/nnano.2015.309 ), and though it is a good bet that led to the recent paper and accomplishment, the new story is an entirely different group unrelated to MIT.

And I'll probably be among the first to buy one if it ever reaches commercialization. The idea of something to compete with LEDs is welcome. It'll still need to at least match LED in terms of overall cost and efficiency. That's a steep hurdle at this point.

 

[jtr1962]

BTW, you know what I consider the biggest problem with LEDs? It's the fact we're intentionally designing many replacement LED bulbs with 10K or 15K hour lifespans, whereas well designed lighting should outlive whatever building it's in. This is producing yet more electronic waste, as if we don't have enough already with people replacing their smartphones every other year.

If we want to mandate anything, I say for all LED bulbs and fixtures we mandate at least 100K hours life under typical use conditions. Buy anything LED, use it for 6 hours a day, and you'll have it at least 45 years. It may have made sense to design for shorter lifetimes when LED efficiency was still increasing rapidly, the theory being why have a fixture last long when it's likely to be replaced in 5 or 10 years with something more efficient. Now that efficiency is getting close to theoretical levels, that concern no longer matters. We should design these fixtures to last at least many decades, even centuries.