You know, it's funny - there's a couple places where this kind of thing seems to have come up. There's research around crop nutrition levels that shows decreases in nutrient levels as yield per acre goes up, there's research on supplements and vitamins that shows synergistic effects between seemingly unrelated substances, we've seen surprising effects from adding or removing species from an ecosystem. One begins to suspect that the "reductive" method of science - the sort of physics- or mathematics-type "reduce the variables of the problem until we can isolate effects" approach - isn't particularly well-suited to dealing with biological systems. You see it in bioinformatics as well - we've sequenced the genomes for many organisms, and have learned a lot from doing so, but we're also learning the limits of that approach pretty strongly - the organism isn't defined just by its 'code', but its environment; the presence, distribution, and concentration of various chemicals; etc. I suspect as we move more towards the "biological" century here we're going to have to readjust how we approach things to start trying to find those synergistic effects earlier in the process, rather than pull everything down to its constituent parts and then experimenting pairwise with various combos. I get the difficulties in doing that, but I feel like we've repeatedly found the stuff we've discarded as irrelevant to the problem ("things that are not in the visual wavelength the eye perceives") in fact do wind up being relevant (wider full-spectrum light has effects outside the mere spatial perception of objects).
You are basically hitting on what has been referred to as high modernism, which promotes a level of confidence in science and technology that can only be maintained by eschewing all the inherent complexity of the world. The scientific method can really only study systems by modifying a handful of variables at a time and keeping the rest fixed, and isn't really capable of handling hundreds of interacting variables. Rather than acknowledge this limitation, high modernism embraces simplification even to the detriment of its products.
> The scientific method can really only study systems by modifying a handful of variables at a time and keeping the rest fixed
Not true. Statistical measures of large systems are a routine thing in the natural sciences. However that's higher effort and tends to make it more difficult to communicate the results to others so it's avoided whenever possible.
Also high dimensional models carry a distinct risk of overfitting.
Could it be the pendulum swinging hard before selling in the middle?
Once we learn from our mistakes we can find the frequencies that do yield the best outcome and at the same time consume (say) ¼ the energy of an incandescent bulb.
Or the minimum set of species yielding optimal outcomes, without the answer being "all of them"
Sounds like a holistics approach will be the next big swing of scientific endeavor.
That was the original point to begin with, right? Learn what makes things tick and then build on that. We've got enough of it down to the atomic level that maybe we should zoom back to the supermolecular.
I have a theory that cheap LED lights with low quality drivers are bad for dogs. LEDs with low quality drivers very often have a high amplitude flicker at 50/60Hz, which is about the flicker fusion rate for humans so we don't perceive it (at least usually), but dogs are known to have a substantially higher flicker fusion rate and probably perceive the flicker. Probably worth considering, especially if you have a dog with epilepsy.
(Incandescents also flicker at 50/60Hz of course, but the thermal inertia of the filament makes this a lower amplitude flicker.)
They also flicker really badly if your power is not perfect, like you have a decent sized training rig on a different circut.
Incandescents are basically little light inductors and I would imagine the luminosity curve would be sinusoidal vs whatever hell a LED driver chip puts out.
I have a theory that they're bad for humans too. I think the same is true for computer screens too. Something about the flickering and the "unnatural" color spectrum messes with people's heads (anecdotal/subjective). Maybe our brains do extra processing work that detracts from other systems.
The newer phosphor-coated "filament" LED's also have this "inertia" which is nice. And no other electronics to fail also since they are just series-connected LED's.
The phosphors do have some inertia, but I'm not sure if it's really enough, since fluorescents have phosphor coatings too and those are notorious for noticeable flicker. Different kinds of coatings though, different thickness and quantities of phosphors, maybe different composition too. I don't know how comparable they really are.
Besides the epilepsy, what do you mean with "bad for dogs?"
Sidenote: My partner and me both "feel" the difference of cheap LEDs. Its not something we can pinpoint down, but it got way better with hue lights.
We live with multiple dogs and iam really curious. One of the dogs that we often had around had severe epilepsy that very strong medication was needed and the dog died anyways way to early around the age of 2. She had less sizures than in her original home when she was with us which ofcourse might be unrelated to the lighting. But your thought is interesting.
When you notice flicker, your iris is trying to expand and contract at that rate to compensate. It was one of the things people were pointing fingers at for sick office syndrome, back when fluorescent tube lighting was popular. People, and I assume dogs, have different thresholds when this problem kicks in and flicker becomes noticeable.
Sibling comments have no clue what they're talking about. I actually engineer these things.
The short answer is cost and heat. What you're describing is a linear constant current driver, which are the gold standard for flicker-free operation. Drawback is a much more complex circuit and a transistor burning off a ton of waste heat.
A constant current driver requires sensing the current across the LED, which involves sensitive analog circuitry. A PWM drive requires essentially nothing more than a FET tied directly to your microcontroller.
There are switch-mode constant current drivers, best of both worlds. Essentially a buck-boost converter in current mode instead of voltage mode. These are slightly more expensive, so they don't appear in consumer lighting products.
All that aside, the reality is that if your PWM frequency is high enough, it doesn't matter. Above several KHz it's imperceptible. The reason that this still isn't done universally is that it's a third of a cent more expensive to use a controller that can switch above 1KHz. All hail the glorious race to the capitalistic bottom.
At work I just finished up a constant current driver circuit. At home I'm building a custom lighting system with bespoke driver circuits. Despite having a CC driver I can pull off the shelf, I still chose 10KHz PWM. It's easier and more efficient, and neither you or I could tell the difference in the quality of the output light.
I used to wonder WTF was so hard about LED lighting. One R, one G, one B, a shunting resistor and... and then I took a glance under the hood. Oh. Yeah, much dicier than heating up some tungsten and frosting the inside of the bulb.
(Yeah, inventing cheap blue LEDs was some serious heavy-lifting in itself, but that hurdle has been jumped.)
Dimming. And even without that, the "continuous DC" is usually provided by switch-mode power supplies that themselves have a PWM ripple. How much depends on the quality of the supply.
Since AC is pulsating you need to store some energy to get continuous DC, usually in a smoothing capacitor. And that capacitor is relatively big and when durable, then not cheap. And it requires some further complications (like avoid inrush current).
There is a 15-30% difference between the groups at baseline (fig 8c-9c, 8d-9d), about the same magnitude as the claimed effect of the experimental condition.
I think the result would be much stronger if these baselines were comparable, so they show they have accounted for other variables like time of day and light history. I am also skeptical of any effect in the retina lasting 6 weeks, with no fading.
Consider that people are often exposed to much more infrared light outdoors, so "worked under a relatively dim incandescent lamp" is not a particularly novel stimulus. Imagine that any of these people spent time outdoors during the six weeks - thousands of times more infrared light there.
The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications. Also, many less expensive LEDs flicker at the rate of the frequency supply of the current (ie 240 or 120 Hz). This is very annoying and related to the instantaneous response of LED vs the averaging effect of the alternating current through an actual glowing hot filament. It is interesting to read on the development of blue and white LED technology.
In the EU this was indeed done for energy efficiency/emissions. Incandescent bulbs were gradually banned from normal sale, starting with the most energy hungry (diffused 100W) and gradually expanding until only low-wattage and special-purpose bulbs were left. Special-purpose bulbs cover a large variety for everything where switching didn't make sense, like machine shops or historic buildings. LEDs aren't mandated per se, but they are the most attractive alternative. And because this all happened before brexit the UK has the same rules, unless they revised any of them post-brexit
For the most part this was a very positive step. Prices for LED bulbs plunged when they went from the "premium" energy-efficient alternative to the default option. But you also get a lot of crap on the market, and stuffing LEDs in form factors designed for incandescent bulbs makes good electrical and thermal design challenging. Even for those brands that actually try
> LEDs aren't mandated per se, but they are the most attractive alternative.
Yeah, basically what the EU did was to say: For X Watts of electricity at least X Lumen of light has to be produced. And this number was gradually increased. Since old school light bulbs are quite inefficient when it comes to producing light, they slowly had to be phased out.
> The push toward LED seems to be primarily for emission target related reasons
Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.
Some cheap LEDs do flicker (at 50 or 60 Hz). But that’s fairly easily solved. I don’t think I’ve noticed the flicker since some cheap bulbs I bought in 2014 or so.
Well… (Sorry, let me put my tinfoil hat on.) Yeah, well that noticed part is what is worrisome to me. I do worry that there is some effect on our brains even though we might not perceive the flicker.
As an analogy, I got into those supposedly audiophile "Class D" (or "Class T") amplifiers over a decade ago. Every day I turned on the music in my office and coded with the T-amp playing. I would have told you at the time that, indeed, it sounded amazing.
Some time later I built a tube amplifier (The Darling [2], in case anyone cares—I've since built perhaps a dozen more).
When I brought it into the office and swapped it out for the T-amp, the change was sublime but immediately noticeable. I hate to fall back on audiophile terminology but it's the best I have for the experience: I was suddenly aware of "listening fatigue" that had been a component of the T-amp. I hadn't even known it had been fatiguing until I heard the tube amp in its place for days on end.
With the loss of color fidelity and the flickering issue, I'm embarrassed to say that incandescent is starting to look good to me again.
I might, as an experiment, replace only those lights that we turn on in the evening when we are relaxing, reading.
If the LED has good DC conversion it should not flicker at all, the flow across the diode would be constant. Just buy good LEDs, incandescent light has many drawbacks.
This is a really interesting comparison, but a flawed analogy. (I’m absolutely not challenging your preference for tube amps.)
LEDs clearly do not produce anything like the spectral energy of blackbody radiation (sunlight, incandescence bulbs), and many do flicker (although that’s a byproduct of individual designs, not the technology itself). This is easy to confirm with simple sensors. So it’s completely uncontroversial to say they don’t replicate “natural” light.
Pretty much all tube amp designs produce an output that is modified from the input signal. This is what makes them sound different and to plenty of personal opinions more enjoyable to listen to music on. But they are more like the “LED” side of the lighting example - they produce an output that is different from the “natural” aka original audio material.
>Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.
At least in EU is true. Citing from Wikipedia: "The 2005 Ecodesign directive covered energy-using products (EuP), which use, generate, transfer or measure energy, including consumer goods such as boilers, water heaters, computers, televisions, and industrial products such as transformers. The implementing measures focus on those products which have a high potential for reducing greenhouse gas emissions at low cost, through reduced energy demand."
I have not found that LED bulbs last noticably longer than incandescents. I'm still replacing bulbs, and though I don't keep records it feels about the same.
LEDs are just terrible in every way except electrical consumption.
Good LEDs in the right circumstances will last almost forever - unfortunately many LEDs on the shelf are trash. They often have small print about not using them in enclosed fixtures or sconces since their thermal management is atrocious and they will self-immolate if not in open air.
If you buy cheap off-brands on Amazon that's what happens. The cheap ones have poor thermal management around the LED drivers, and the heat dissipated will eventually burn the drivers out, much sooner than is reasonable.
Hooray shitty capitalist incentives.
The non-cheap LED bulbs I've bought have all lasted years and years. I do have some cheap ones that are starting to fail, after just a year or so. (Problem with those is that it was really hard to find the correct bulb size and connector type, so my options were limited.)
It does seem an easy win for govts to easily conform.
I buy the ones that are suitable for dimmable switches (even tho I don't have dimmers) because there is discernible flicker with most other LED bulbs if you for eg wave your arm through the air or made a saccade. There is a certification (i think) for LED bulbs that are closer to
sunlight in their emission spectrum
LED bulbs, even though cheaper in the long term, used to habe high enough shelf prices enough that most houdeholds wouldn’t have switched without a government push. Incandescents are literally banned now for most uses, while the economies of scale have helped drive LED prices down.
It costs less to run because less energy is used; I'm pretty sure incandescent bulbs aren't emitting anything by themself!
"The push" is from the government, perhaps consumer demand is "the pull".
Almost all the energy consumed by appliances in your home gets ultimately converted into heat. For example, the picture on your TV is made from emitted light rays that are absorbed by various solid objects in your home and heats them up. Same for the sounds from your speakers. Your washing machine spins water and clothes around, which makes both the water+clothes and the body of the washing machine to heat up due to friction.
A counter example is a water pump, which converts electricity into gravitational potential energy of the water as it flows upwards.
Not sure about the point of your comment. Ok, doing work generates heat. But if the primary goal is to generate light, not heat, then incandescent bulbs are terrible at their job.
which is not that bad if you want to warm your room a bit. The heat is not wasted, but added to the room. We use 250 watts to warm under the coffee tables. These are infrared-coated incandescent bulbs
The flickering is solely a result of cost cutting in the power supplies of these LED lights. The problem is totally solvable with a constant current switching power supply. But the filtering circuitry adds cost.
The problem is that consumers usually cannot know this about a particular light (or a lot more) at the point of purchase, so even if you are willing to pay a premium for this you cannot.
I would pay a premium for longer life, and at least in some cases (e.g. lights I read by) for better quality. How do I do so? I would love to be pointed at sources of better ones (in the UK).
In the EU, lights have to be sold with a mandatory energy efficiency label. A lesser-known component of this is that this label includes a link to a standardised datasheet, which includes things like flicker metrics, CRI, chromaticity, and a measurement of the spectrum.
It doesn't fully quantify the light, but it's good enough to distinguish trash or even passable lights from actually good ones.
tl;dr: Just buy Philips UltraEfficient (I think these are roughly equivalent to the infamous "Dubai Bulbs"[1]) or Ultra Definition bulbs. They cost a little bit more but will probably pay for themselves over the years.
Buy name brands with a history of putting out decent bulbs instead of the Amazon alphabetsoup brands that won't be around in 5 years (although TBF some of my cheap BogAo bulbs are still going strong after 8 years). You can get a good feel for the light's "quality" by looking at the CRI and color temperature.
For CRI, anything 90+ is good.
For temperature, IMO around 3000k is the sweet spot. go higher if you want sterile operating room vibes or lower if you want super yellow/orange cozy hobbit hole vibes.
> The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications.
Can you even buy them without buying new old stock? In the US they're banned and there's zero production.
I recall there was a guy in the EU who tried to get around the regulations by selling "heat bulbs" that were exactly the same as traditional incandescent bulbs but marketed as a heat source, but I think he was slapped down.
At least in Germany you can still fairly easily get 20W incandescent lamps. Sold as lamps for fridges and ovens, but they are available with standard sockets.
If you look around a bit you can also get 60W or 100W lamps, sold as "industrial lamps" or "extreme temperature lamps", labeled as unsuitable for household use. But those are specialty lamps that you won't find in your local supermarket. Not sure if those are new old stock or imported
Certain size/watt combos are still available for things like appliances and nightlights, but I think that includes 20W E26/A-something bulbs, and the bulbs for plug-in night lights. I can still find them on the Home Depot and some other places. No idea about quality but I still prefer how they look. There are so many other horrible energy efficiency problems with heating my home that the inefficiency of a few incandescents in key places doesn't bother me in comparison to the enjoyment I get from the nice light.
If I were able to see the flicker of mains supplied LED lighting (which I cannot), then I would be very tempted to install low-voltage DC LED lighting, which presumably does not flicker.
An AC/DC power converter works the same, either built into the bulb or in a separate unit. But yes, a separate power converter is almost certainly going to do a much better job of removing the 50/60Hz voltage drop. Not sure if it would be cheaper, given the economies of scale on AC bulb manufacture. Higher quality AC bulbs may come out ahead for flicker free lighting.
It only doesn't flicker if there's no power driving circuitry - eg just LEDs and a resistor.
Otherwise, if there is a power IC present, there is flicker, though fast enough for most humans to not perceive normally (you can still check it by waving your hand in front of the light and seeing the strobed afterimage.)
That's not strictly true. The very simplest of DC LED drivers flicker, such as the classic single-transistor battery saver circuit, but a slightly more complex DC LED driver circuit will not. One of the best ways to drive an LED is with a constant current source, which typically involves putting an inductor in series with the LED and switching the supply to that at a reasonably high frequency, which would mean the LED does not flicker at all.
If it's hooked directly to AC power, isn't there by definition a flicker? With a power IC, a poorly implemented power circuit will also visibly flicker. With high enough rate and the right power characteristics it should not be noticeable. Do you notice flicker in a quality phone or monitor screen?
Very interesting. I've always thought that there was something a bit "off" about LED torches and car headlamps; the brightness is there, but something about the light just doesn't seem to illuminate as well as an old dim incandescent or even fluorescent tube.
It's usually the Color Rendering Index (the spectrum of frequencies that the light puts out). Incandescent bulbs more of less mimic that of the Sun, they are "black body radiators". Cheap LEDs tend to be missing a lot of the red spectrum.
However, you can get LEDs that do this well. Look for one with a "CRI" of 95% or higher.
There's a massive difference between the 2600K of regular incandescent bulbs, and the 6000K of sunlight. That's why hollywood used HMIs until they migrated to LED.
For professional applications there are sulfur plasma lamps which have a continuous spectrum at high efficiency. Unfortunately they aren't economical below about 1000 watts which is impractical for many applications.
The technology basically works by continuously microwaving (think oven) a small amount of sulfur gas. The development of solid-state microwave emitters — most microwave generation is still done with vacuum tubes — might help miniaturize the devices. However, it's hard to beat the simplicity of an LED.
There is, but most humans are used to the spectral pattern of black body radiators at all color temperatures. Be that sunlight at higher temperatues or fires / candlelight at lower temperatures.
Regular exposure to fire/candlelight has only existed for a hundredthousand years, while mitochondria have existed almost unchanged for millions of years.
So even that assumption would require further study.
They're saying that the visual performance is indirectly affected by invisible wavelengths somehow. Not that you can see the difference between two types.
They are saying that, and most real world LED lighting uses very cheap diodes, like, 99.9999% of them, which create very poor colour compared with incandescent bulbs, which create perfect colour representation.
It's a big thing and you can buy LEDs which produce a better colour range, but they're much more expensive and not as energy efficient, because creating bold reds costs hard energy that no diode trick will ever get around that.
>They are saying that, and most real world LED lighting uses very cheap diodes, like, 99.9999% of them, which create very poor colour compared with incandescent bulbs, which create perfect colour representation.
Have you actually read the study? It's about infrared and has nothing to do with color rendering and visible spectrum. They're vaguely speculating about some mitochondrial mechanism of action not related to vision at all.
That's the interesting thing about this study. A lot of people here are speculating around explanations connected to metamerism, but the control (Figs 7 and 9) partly rules that out.
I get that they're more efficient in some sense, but man the LED streetlights and other big lamps are so irritating and make things like like such ass compared to mercury vapor or even sodium lights.
True. Yet, somehow more and more cities install them blindly because efficiency. I remember when I moved to Odense Denmark in 2013 - they had LED street lights all over the place. I thought - this is the future compared to my uderdeveloped post soviet Latvia. And yet, I remeber when I moved back, streets at night looked so yellow because the city still relied on sodium lights. And my eyes felt much more comfortable. At the time I wrote it off to nostalgia or something, and here we are.
For LED lamps, the color must be controlled at the emission source, not by filtering, i.e. by using an adequate combination of different conversion phosphors, to ensure a neutral white with a quasi-continuous spectrum, instead of a bluish white with great narrow peaks in its spectrum.
Unfortunately, the phosphors for the latter variant are much cheaper than for the former, so the lamp vendors have the incentive to make the lamps as bad as possible.
I ask only because I was retrofitting some navigation lights on a sailboat - and you can’t just upgrade the original incandescent bulbs with LEDs (or aren’t supposed to).
You are either supposed to get a special LED (backing up what you’re saying) or there are some new red/green enclosures that are differently treated / tinted to then put a “white” led into.
But I am so far from an expert on that, I may be completely misunderstanding.
When you use any kind of filter for a lamp, that stops a part of the light produced by the lamp, the part that has an undesired color.
So, at the same electric power consumption you have less light, or you can compensate by using a more powerful lamp, to get the same amount of light even with a filter. In both cases the energy efficiency becomes worse, i.e. the expenses for electric power are greater per output light.
On the other hand, when the manufacturer of the lamp controls inside the lamp the conversion of the light produced by the LED through fluorescence into the light that exits the lamp, there are chances to obtain a desired color and a certain shape of the emission spectrum by wasting less light than with external filters.
Filtering can correct a lamp color that is not the color that you want, but it cannot fill gaps in the emission spectrum of the lamp.
Cheap white LED lamps not only may have a too bluish color (or in some cases a too yellowish color), but their emission spectra may have gaps, so if a natural object from the environment happens to have a color that falls in a gap of the LED lamp spectrum, it will appear much darker than in daylight. This can cause orientation problems or difficulties in identifying certain things.
Where LEDs are used for signalling, not for lighting, so pure colors are desirable, much less problems exist, so e.g. the replacement in the red or yellow signal lights of cars, of the old incandescent lamps with color filters, with monochromatic LEDs without color filters, has posed no difficulties.
Yes lots of them use cheap LEDs with poor CRI, high color temperature, and a huge blue spike in the spectrum. All of that leads to a very bright looking light that also doesn't let you see detail very well.
Just to point to anybody that comes here directly, the article has no relation at all with perceived illumination, color fidelity, or anything else people complain about leds.
It's an interesting niche topic that you may want your working place to notice if you work indoors.
I’ve always been mildly bothered by the LED lighting in my home, as if it’s simultaneously bright but not illuminating. In simple consumer terms, if I wanted to shop for a variant that more closely replicated incandescent lighting, what exactly am I looking for on the packaging? Or does this not exist?
It’s called SSI, spectral similarity index. SSI is specified for a color temperature, eg 3200 or 5600. 100 is identical to tungsten or sunlight. Values above 85 are good.
In the UK I've not been able to find high wattage (10-20W) LED lightbulbs with high CRI, some don't even mention it in listings, let alone SSI, which I have never seen.
Where are you seeing these? Is this industrial/commercial suppliers?
I buy the "warm" light LEDs, which look (to my eye) closer to incandescents.
Standard LEDs bulbs are bright white, almost bluish, and yes "bright but not illuminating" describes them well. I feel many modern car headlights have the same issue.
The human eye doesn't focus the blue end of the spectrum very well.
There is no such thing as a “standard LED lamp”. LED lamps come in a huge variety of shapes, various bases, power usage/lumen output, color rendering index, and color temperature.
Lots of companies sell cheap crappy A19 E26 base 5000K lamps, that doesn’t make them the ‘standard’.
Nothing on the box really means anything, so many bulbs claim high CRI and everything but in reality have terrible spectrum. So you can only go off of actual real life testing from a third party.
No mention of CRI which seems kind of odd. LEDs for lighting are increasingly graded by how natural their emission spectrum is. Older lights are quite bad, newer ones sacrifice a tiny bit of performance for more uniform spectrum.
They use rf numbers, which is a newer standard, so that's probably good.
However, the experimental group (extra light sources) got rf 91 bulbs, and the control ("LED lighting") got rf 85 bulbs.
The two scales are not exactly comparable, but they both max out at 100. The only source I could find that discusses both says that > 90 CRI is "excellent" and just below that is "very good". It says > 85 rf is "very good", which tells me it's comparable to a mid-80's CRI bulb.
If I accidentally buy a mid-80 CRI bulb, I either return it to the store, or just throw it away.
So, I'd say this study's experimental setup doesn't support any useful conclusions. They showed that so-painfully-bad-California-won't-subsidize-them LEDs are worse than passable LEDs with supplementation from another light source.
The passable LEDs in the study are probably comparable to the cheap ones at our local hardware store, but worse than the ones that cost $10-20 on amazon ten years ago.
This would have been much more interesting if they'd compared high-end LEDs with and without supplementation, and found a difference. (And by "high-end", I mean "still much cheaper then the electricity they save")
I think CRI is not important here as thats a measure in the visual spectrum. The paper talks about all the missing wavelength outside of the visual spectrum.
CRI is a pretty bad rating system. They are showing the full spectrum graphs which is what you'd want anyway. Spectral Similarity Index (SSI) is the better number
Sure, but I don't see them mention what they're actually using for LEDs at all. They mention a "colour fidelity index" but I'd expect a manufacturer part number or something so I can pull the datasheet.
Funny enough, the best evidence for this study is that they should probably move somewhere with more sunlight if they can't spell "color" right... /s
What is the relationship between CRI and how broad (or narrow) the spectrum output by the LED is? Is CRI automatically better for broader-spectrum LEDs? Or is that too simplistic?
Slightly overly simplistic because the broader-spectrum LEDs could be broad-but-spikey for their output, resulting in light that is broad spectrum, but has a bad CRI (because it's eg really blue).
It was known among MTB riders who ride at night sometimes: typical XM-L T6 Chinese headlights were unusable in the forest when you move fast. Good diodes (like Nichia 219B) worked. And XM-L was dominant even in very expensive «brandnamed» lights for many years (you could buy Aliexpress headlight for $20, you could bu "Italian" lamp for $250, result is the same)
I'm not in this scene anymore for many years, but when I was, I built my one lamp from custom light engine (essentially round PCB with DC-DC current limiting schematics an LEDs) with 3x219B, Chinese body and CARCLO TIR Optics...
Seems like this is only relevant for people who don't go outside for weeks at a time? This article has a strangely "pro-long-wavelength" tone, yet sunlight also exposes you to UV frequencies that are so harmful according to this paper.
Was just discussing last week with a colleague how for the same 'lumen' there was such a dramatic difference between led and incandescent bulbs for ease of reading paper books.
There are very great differences in light quality between various kinds of LED lamps.
You may have various LED lamps, all of which appear to have the same white color, but their spectra are very different. Those with narrow spectral peaks are very bad lighting sources, while those with wide spectral peaks, achieved by using multiple kinds of conversion phosphors, are much better lighting sources.
With the best LED lamps, there is not much difference in comparison with incandescent lamps. While incandescent lamps are best from the point of view of their continuous spectrum, their yellow light strongly modifies the perceived colors. While bluish white LEDs (e.g. of 6500 K color temperature) are also bad, neutral white LEDs (e.g. 5000 K or 5500 K) provide much better color perception than incandescent lamps.
For home lighting I prefer a white that is only very slightly yellowish, i.e. 4000 K lamps, instead of LED lamps with a higher color temperature or of incandescent lamps, which are so obviously yellow that no clothes have the same color as in daylight.
The best quality of lighting can be achieved by incandescent lamps in conjunction with frequency-selective filters, which modify their spectra to resemble the spectra of a blackbody with a higher temperature, like the Sun.
Such filtered incandescent lamps were used a very long time ago, to provide lighting for color photography, movies and television (e.g. for the original white point of NTSC), but they were abandoned due to high cost and due to an exceedingly low energy efficiency.
As I have mentioned in another comment, filtered incandescent lamps might see a revival, but implemented with very different technologies than those used a century ago.
I use 90CRI LED lights where I study. They are Philips' non-flickering, dimmable, High CRI bulbs, yet my classic 25W halogen table lamp still provides a far better reading experience. The spiky spectra of LED lights are not comfortable for eyes as a full-spectra incandescent light, let it be classic or halogen.
90CRI isn't good enough to replicate an incandescent bulb in my experience. Something in the high 90's can be much better (but admittedly hard to find). And of course you may want to match your preferred color temperature too.
Actually, this is the best I was able to find. The prices increase almost exponentially when you try to go to higher end of anything, and I was not in a mood for digging whole city and the internet for a single bulb. A Philips' 90CRI bulb is already a great upgrade from an 80CRI bulb, so I ran with what I was able to find in a pragmatic time frame.
For reading black & white text, incandescent lamps are perfectly fine.
However, if your book has color illustrations, a high-quality neutral-white LED lamp is better than any unfiltered incandescent lamp.
A standard white illuminant with filtered incandescent lamps would be even better, but such lamps, as they were made a century ago, were extremely good space heaters, which may prevent their use for reading a book.
The OSRAM halogen lamp I use has special filters, and looks greenish when it's turned off, so it might not be a "brute force, let everything through", 25¢ halogen lamp. The bad thing is it's not being produced anymore, but I have a couple of spares.
I went through university with the same lamp/bulb, so that combo doesn't create the unwanted reflections much. Also, I still print everything in color, because a good color choice still boosts understandability of the material at hand.
It’s a shame that grift claims everything.. once upon a time, Huberman was a serious person but he’s now just Joe Rogan with an advanced degree - platforming all sorts of bullshit for a check. At least there are other sources listed though so thanks for those.
It should be noted that even if we assume that the conclusion of this study is correct, i.e. that artificial lighting should have a wide spectrum including near-infrared light, that does not mean that returning to classic incandescent lamps is the right solution for this problem.
The incandescent lamps with tungsten filaments have a much lower temperature than the Sun, thus much more energy is radiated in infrared than needed.
There was about a year or two ago a discussion about a very interesting research paper that reported results from testing an improved kind of incandescent lamp, with energy efficiency and lifetime comparable to the LED lamps.
The high energy efficiency was achieved by enclosing the lamp in a reflecting surface, which prevented energy loss by radiation, except for a window that let light out, which was frequency-selective, so only visible light got out, while infrared stayed inside. The lamp used a carbon filament in an environment that prevented the evaporation of the filament.
With such a lamp, one can make a tradeoff between energy efficiency and the content of healthy near infrared light, by a judicious choice of the frequency cutoff for the window through which light exits the lamp.
Even with enough near-infrared light, the efficiency should be a few times higher than for classic incandescent lamps, though not as good as for LED lamps. Presumably, one could reach an efficiency similar to that of the compact fluorescent lamps (which was about half of that of LED lamps), for such an incandescent lamp that also provides near-infrared light.
How does enclosing the lamp in reflective material help with the energy efficiency? Isn't the infrared radiation emitted anyway? Doesn't that make the lamp overheat?
If the reflective material is ideal, by definition no infrared or other radiation is emitted.
Perhaps I was not clear, but the reflective surface was the interior surface, so it reflected any light, visible or infrared, back towards the emitting filament, while the front window reflected only the infrared, while transmitting the visible light.
The lamp does not overheat, because the filament is kept at a constant temperature, the same as in a classic incandescent lamp. The difference is that you need a much lower electrical current through it for maintaining the temperature, because most of the heat is not lost away, like in a classic lamp. The fact that you need a much smaller electrical current for the same temperature is the source of the greater energy efficiency.
Only if you had used the same electrical current as in a classic lamp, the lamp would have overheated and the filament destroyed, but you have no reason to do that, like you also do not want to use in a classic lamp a current higher than nominal, which would overheat and destroy it.
Also even limited to visible spectrum, I have not seen any 99 CRI bulbs. The highest one I have ever found are the 98 CRI by YujiLED, but you pay around $35 for a single bulb. It is absolutely not "easy" to get flicker-free high CRI bulbs, let alone ones that cover the infrared range.
Phillips, GE, Cree, and others sell high-CRI bulbs.
10 years ago you had to work to find high CRI bulbs but could still find Cree bulbs pretty easily. Now you can get high CRI bulbs at the grocery store.
High CRI bulbs generally have low or no flicker because high CRI is toward the premium end of the market.
Almost all of the bulbs you can find at a hardware store (let alone grocery store) exhibit terrible 120hz flicker. I know because I've literally tried every single one. Also it's not hard to get "high" (~90-94) CRI while nonetheless having terrible deep reds.
Out of the manufacturers you listed, only Philips Ultra Definition (95 CRI, R9 90) have low flicker and good R9. Unfortunately they are poorly made and I have to keep buying new packs each year but it's more cost effective than Yuji for lesser used areas.
Also the claim from TFA is that NIR component improves visual performance (and I've read elsewhere that NIR also has health benefits).
How about Phillips flicker-free "warm glow" bulbs? I honestly have a hard time believing that they flicker because I can literally unscrew the bulb and watch it dim gradually over the course of a second. Which indicates to me that there's a capacitor in front of the LED drivers smoothing the current out. (Which I guess is required to be compatible with triac dimmers anyway.)
Never tried those, but speaking about flicker, some LED lamps flicker not because of the mains frequency (50/60 Hz depending on where you live) but because of their internal switching power supplies.
It's mostly a crapshoot even within the same model line. Even under "Philips UltraDefinition" some styles have high flicker while others don't. I'm not sure being dimmable is any guarantee of smoothing quality, in fact dimming is usually implemented with PWM as I understand so the easy solution to avoid flicker of chucking a smoothing capacitor on there might make it harder to implement dimming. (To dim properly without noticeable I think you'd have to PWM in the kHz range. Even cheap CFLs necessarily had the technology to operate on this frequency, for some reason it seems rare for LEDs to do it.)
They are specifically advertised to be compatible with old dimmers. I'm not an EE but old dimmers are implemented with triac which necessitates some juicy capacitors to hold the charge. Of course they could reintroduce flicker later in the pipeline for some reason, but why would they?
Huh, through experience with (mostly non-premium) LED bulbs, I've learned to interpret "gradually dims over the course of a second" an an early indicator of imminent bulb failure.
If you look at energy efficiency, it totally is. But the whole point in the discussion is that IR _might_ (according to the paper) have biological relevance.
You can't buy heat lamps? They are even more infrared and last longer.
Also LED lighting can have infrared, have a significantly more smoother spectrum curve and still last +20k hours without burnout. The cheaper bulb spectra that they show is a blue led + phosphor coating, but there are infrared LEDs, UV leds, and more. You can make quite the convincing sun simulation, even better than any incandescent bulb, but there is almost no demand for UV + Infrared super full spectrum lighting unfortunately. Only movie & theater lights come close.
>LED lighting can have infrared, have a significantly more smoother spectrum curve and still last +20k hours without burnout
Do you have a link to a bulb that you can purchase meeting all these criteria? The only one I'm aware of was this obscure "StarLike" that was never actually sold in bulk. LEDs can be made good in theory sure, but in practice they are all terrible in light quality compared to a standard incandescent.
You would need to see the spectra of the various LEDs available and create a mix along with phosphor mixes. The closest thing is something like a BLAIR-CG light engine from aputure where they have something like 9 different colors of LEDs that mix together, but they don't put any infrared leds in them because they are for movies and they don't put any UVB or proper UVA leds. But there are infrared, UVA & UVB LEDs that you could apply the same kind of engineering principle to make something that closely follows the sun spectra.
No, you can't buy them as bulbs. The closest thing is those red light therapy panels that include them.
There are efficiency standards and laws for large appliances.
This isn’t some kind of controversial subject. Ensuring home appliances don’t overconsume energy is beneficial for everyone in society.
You don’t want to have brownouts, blackouts, or run out of heating gas/oil in the winter.
You bring up the idea of regulating computer equipment power efficiency as if it’s crazy talk but it’s a real thing in concept. Governments do offer guidance and sometimes regulate computer efficiency. They have efficiency standards (e.g. Energy Star) as well as relying on industry standards (e.g. “80 Plus”).
Take a look at your computer monitor or TV box and it probably has an energy star logo somewhere if you live in the US.
The US federal government and other state and local agencies will not buy computer products that aren’t energy star compliant, and encourages businesses and individual to follow similar standards. Other countries might regulate further than these (dis)incentives.
And if you bring up data centers, those are considered productive industry that has its own regulations different than home regulations. Plenty of things legal in industrial series aren’t legal in your house.
High-powered computers are a niche issue, which means on a society level there's little benefit to restricting them.
Lightbulbs on the other hand affect all of society, so they've got a much larger impact to the overall CO2 budget.
Additionally, the average person uses a laptop or mobile devices, all of which use less power than even a single typical incandescent bulb (and people usually have many lightbulbs).
Replacing incandescent bulbs with LEDs saves a lot of CO2 at basically zero cost, while getting rid of computers saves less CO2 for a much larger economic impact.
And even the effect described by this article has to be looked at in context, considering most of the light people experience in a day — and have experienced for the since homo sapiens existed — is natural sunlight, even in northern Europe during the winter (that's why EU law mandates windows with sunlight in every office, apartment, bedroom, etc.)
I find it a little strange that there is no real discussion of limitations in this paper. They mention the limitations of something they cite, but nothing about the data they themselves collected or the conclusions they draw from it
I've been using incandescent more often. All my vanity lights are 40w appliance bulbs now. The difference at night is remarkable. The LED is just too much even at 2700k. I still prefer LED for high power situations like br30/40 can lights.
I found some interesting tidbit about this bigger issue. And I want to share how to more easily check it.
We many times see some people reporting that they clearly see lower quality LED light flicker and is really distracting to them and even causes them headaches.
Now, I didn't see this until recently (unless in failing lights) in the right conditions. If the light is very, very dim: For instance, only 1 light on in the night, and you are in a division far away from the light so that it's extremely dim. There, I could finally really see it flicker.
I've replaced that light for a better one and the effect went away.
There are some full spectrum led lights, they just cost over $100 a piece. And they might get banned in the future for not being energy efficient enough.
Scientific Reports is a junk journal fyi. Not conclusive, but indicative.
Despite saying the visible flux component is "small" and that the tungsten lamps "were not expected to [be used] as task lamps," Figure 6 (a) and (c) shows... desk lamps right at the work stations like task lamps! Not only is this experimentally unblinded, but the visible light immediately in front of the test subjects is noticeably brighter and warmer. The effect could simply be due to reduced eye strain.
What would James Randi do? "Extraordinary claims require extraordinary proof," and unfortunately this isn't it.
This would be more interesting if they add a visible light filter on the lamps so they only emit infrared radiation, and have an identical double-blind control with a 60 watt heater bulb so it emits no SWIR but the same radiant heat (which could confound and/or unblind).
This should also be true for TL lights. Which kinda contradicts common sense seeing that those are used all over the place in offices, kitchens, and hospitals, makes me think this paper is bogus.
Yes, there is something obviously wrong with most LED lights, but it isn't too much of short wavelength light, but on the contrary. It's the near absence of cyan light in most LEDs. Our eyes are by far the most sensitive to it, the majority of receptors in the eye are sensitive to it, and we may focus primarily on it (focus differs for different wavelengths). This is how you get the feeling of something being wrong with your vision as you for example walk into a mall, and so on.
If anything, higher temperature lights seem to make it better, not worse, but the problem will persist as long as the cyan hole stays there.
Sensitivity peak for humans is in cyan (~510nm) only for low-light conditions (night vision / rod cells). In daylight (cone cells) it's green-yellow (555nm).
https://www.giangrandi.ch/optics/eye/eye.shtml
>The eye behaves differently in high or low light conditions: in daylight, for brightness levels above 3 cd/m2 the vision is mainly done by the centre of the retina, we can see colors and the maximum sensitivity is at 555 nm (in the green region). This type of vision is called photopic vision.
That's completely impossible, you would have severe tunnel vision in daylight, if it was true.
There has never been any real evidence that rods stop working in daylight.
wouldn't this be a good thing? I prefer my circadian cycles not to be disturbed by artificial lights and if i am reading this right, it is what happens with led lights. this would be different of course if i had no access to natural lights. glad to be corrected :)
The authors, bless their hearts, suggest that running halogen lamps at lower-than-rated voltages might be a good idea.
> If this is done with a halogen bulb, which is a type of incandescent tungsten bulb, the filament lasts for a longer period as evaporated tungsten is redeposited on the filament rather than blackening the bulb glass. Hence, using a halogen bulb at lower voltage is a realistic alternative in terms of health and energy consumption.
Unfortunately, as I understand it, the redepositing action only occurs at high temperatures.. It's a chemistry thing. I have been led to believe that running halogens at low voltages will cause the bulb glass to blacken sooner. See https://en.wikipedia.org/wiki/Halogen_lamp#Effect_of_voltage...
I hate the LED street lamps so much. I can tell they've got a really spiky and unnatural spectrum, unlike the HPS lights, not to mention that they're white or bright yellow...
Even to this day when I'm on the bus on the highway it's so relaxing and comforting to ride through the orange lights.. then the bright white ones come through and it's almost like instant anxiety that kicks in
I have incandescent light bulbs at home I have to pretty much smuggle from China. It's amazing how we're replaying the asbestos playbook a century later. Only this time it's government mandated.
Asbestos was pushed as a magical solution to problems of fire in homes without paying attention to the health effects. It took 80 years for the obvious to become law.
Leds are pushed as a solution to energy consumption by humans without paying any attention to the health effects. Hopefully it will be less than 80 years of cancers and metabolic disruption before the obvious is done.
But this time the regulation was captured pre-emptively, to the point that following best scientific advice for your health is illegal is most of the developed world.
LEDs being ugly or causing eyestrain is one thing. But cancer? There's very little chance that LED lighting causes cancer. We don't have a plausible mechanism for that.
There are no white LEDs. Just blue LEDs with coatings that convert a fraction of blue/violet light into lower energy colours. They work the same way that fluorescent light do.
> But this time the regulation was captured pre-emptively, to the point that following best scientific advice for your health is illegal is most of the developed world.
Please cite your sources then. And no the other article you linked is not proving your claim
There's a mostly-unsubstantiated-by-data belief that LED lighting can cause health problems by some combination of flickering and narrow color spectrum.
There's a mostly-unsubstantiated-by-data belief that LED lighting can NOT cause health problems by some combination of flickering and narrow color spectrum.
Where does this article mention LED lights vs other types of artificial light-at-night?
What I could find regarding light color:
> However, most studies relied on satellite-images with a very low resolution (1 to 5 km, from the Defense Meteorological Program [DMSP]) and without information on color of light
> noted that data quality suffered from many limitations due to the types of satellite images used and the focus in the vast majority on visual light levels only rather than considering the circadian-relevant blue light component, among others. Future studies should consider improved satellite-based ALAN technologies with improved resolution and information on spectral bands and apply these technologies to a variety of cancer sites to yield better estimates for the potential risks between ALAN and cancer.
So nothing conclusive about LED being bad for your health (vs other types of light).
You're playing so defensive (for LEDs) wonder why - just to argue? If one uses the same logic - does anybody states that LED are GOOD for the health? What the lack of such statements means - they're bad, or have no effect?
At the end - is it your business at all if I want to use incandescent lights, or CFLs, because I find them more suitable for my personal needs in MY home?
No I just refute a claim on which the provided source does not prove or indicate in any way.
I'm not arguing LED to be better or worse, I'm just looking at a proof of some kind to what is argued.
But it seems like it's too much to ask? I should just accept whatever comments I read without any critical thinking?
Looks to me that _you_ conclude it's related to LED, I couldn't find that stated in the abstract, it might just be related to a general increase of artificial lightening, regardless of the source.
I’m guessing the Russian theory that asbestos is totally fine and isn’t harmful? The Russians still use asbestos and say it’s a plot by the west that we got rid of asbestos in our buildings. (Don’t shoot the messenger here, I have no dog in this fight and am not expressing an opinion)
Asbestos is totally safe as long as it’s not friable and you don’t sand it or disturb the fibers. Mesothelioma was a major problem if you were repeatedly exposed to asbestos. It’s present in nature and especially in soil in small concentrations. What makes it dangerous is if you’re constantly breathing it in. You would be doing that if you ran a buffer over asbestos tile for years, or if you worked in a space with asbestos pipe insulation, or if your job was to install asbestos siding or sheet flooring or formica(many adhesives contained it). Even gypsum wallboard contained asbestos up through the 80’s. It’s precisely its ubiquity as a building material that makes it dangerous because people are constantly disturbing it occupationally.
The problem is that not disturbing the fibers is impossible if you work with it at all, and workers in Russia still suffer from life-changing injuries. Disposing of it safely is also not realistically possible. The regulator just doesn't care, it's as simple as that. Of course they don't "think it's safe" as GP said, there's a ton of research and practice on the opposite and they set a specific (pretty low) limit on the exposure. But they turn a blind eye to the fact it's impossible to enforce and will never be followed in practice as long as asbestos is still being used anywhere. This is why asbestos use is banned everywhere, and this is the issue with Russian regulations, they give a tiny bit of economy a priority over public health, using the convenient research that pretty much "натягивает сову на глобус" in trying to downplay the hazard, if you actually read the relevant studies in Russian.
Why is it that right now there is still on the frontpage of an "article being found flawed after 6k citations " ( https://statmodeling.stat.columbia.edu/2026/01/22/aking/ ) but this random article coming out of nowhere makes the front page on the same day?
People really should get it and stop sharing newly published papers to the general public. The value of one single academic paper is exactly 0. Even a handful of such articles still has 0 value to the general public. This is only of interest to other academics (or labs, countries, etc.) who may have the power to reproduce it in a controlled environment.
Be very skeptical of correlations like this that have dubious or poorly understood causation. Be even more skeptical if they are about day-to-day stuff that would likely have large swaths of people able to reproduce something like it on huge scales yet they haven't. Extraordinary claims require extraordinary evidence.
This article is not making an extraordinary claim, and your offence is hyperbolic. Analysis of research should not be restricted to the academe, but careful not to cherry puck research.
Considering the percentage of live mitochondria that are exposed to external light in a human this seems like an enormous effect. The effect we'd expect from publication bias though is already pretty big. I'm going to go with the latter until we've got some replication, and a plausible mechanism (like.. why wouldn't whales be badly sick if this was a thing?).
I don't know about the mitochondria bit, but it is plausible that work performance is affected by light spectrum. The n=22 is too small, but replication or larger studies is an obvious next step. Let's hope the researchers in this field use pre registration.
The article mentions that unlike visible light, which is mostly absorbed by the skin, near infrared light penetrates deep into the body and the lowest frequencies of the Solar spectrum pass through the entire body.
This explains why most mitochondria are exposed to infrared light, even those deep in the body.
The article also mentions an inhibiting effect of blue and violet light upon mitochondria. For that it should be valid what you say, that this effect can happen only in the superficial layer of the body, because both skin and blood strongly absorb such light.
Even if that is true, we humans tend to have clothes on, and keep indoors. Considering that the sun is WAY brighter (several orders of magnitude) than fluorescent bulbs are, this still sounds implausible, if you compare it to just going outside for a while.
You know, it's funny - there's a couple places where this kind of thing seems to have come up. There's research around crop nutrition levels that shows decreases in nutrient levels as yield per acre goes up, there's research on supplements and vitamins that shows synergistic effects between seemingly unrelated substances, we've seen surprising effects from adding or removing species from an ecosystem. One begins to suspect that the "reductive" method of science - the sort of physics- or mathematics-type "reduce the variables of the problem until we can isolate effects" approach - isn't particularly well-suited to dealing with biological systems. You see it in bioinformatics as well - we've sequenced the genomes for many organisms, and have learned a lot from doing so, but we're also learning the limits of that approach pretty strongly - the organism isn't defined just by its 'code', but its environment; the presence, distribution, and concentration of various chemicals; etc. I suspect as we move more towards the "biological" century here we're going to have to readjust how we approach things to start trying to find those synergistic effects earlier in the process, rather than pull everything down to its constituent parts and then experimenting pairwise with various combos. I get the difficulties in doing that, but I feel like we've repeatedly found the stuff we've discarded as irrelevant to the problem ("things that are not in the visual wavelength the eye perceives") in fact do wind up being relevant (wider full-spectrum light has effects outside the mere spatial perception of objects).
You are basically hitting on what has been referred to as high modernism, which promotes a level of confidence in science and technology that can only be maintained by eschewing all the inherent complexity of the world. The scientific method can really only study systems by modifying a handful of variables at a time and keeping the rest fixed, and isn't really capable of handling hundreds of interacting variables. Rather than acknowledge this limitation, high modernism embraces simplification even to the detriment of its products.
Further reading: https://en.wikipedia.org/wiki/Seeing_Like_a_State
> The scientific method can really only study systems by modifying a handful of variables at a time and keeping the rest fixed
Not true. Statistical measures of large systems are a routine thing in the natural sciences. However that's higher effort and tends to make it more difficult to communicate the results to others so it's avoided whenever possible.
Also high dimensional models carry a distinct risk of overfitting.
Complex system / ecosystem literacy is important, but this infrared thing is just junk science unfortunately.
https://news.ycombinator.com/item?id=46764382
Could it be the pendulum swinging hard before selling in the middle?
Once we learn from our mistakes we can find the frequencies that do yield the best outcome and at the same time consume (say) ¼ the energy of an incandescent bulb.
Or the minimum set of species yielding optimal outcomes, without the answer being "all of them"
Sounds like a holistics approach will be the next big swing of scientific endeavor.
That was the original point to begin with, right? Learn what makes things tick and then build on that. We've got enough of it down to the atomic level that maybe we should zoom back to the supermolecular.
I have a theory that cheap LED lights with low quality drivers are bad for dogs. LEDs with low quality drivers very often have a high amplitude flicker at 50/60Hz, which is about the flicker fusion rate for humans so we don't perceive it (at least usually), but dogs are known to have a substantially higher flicker fusion rate and probably perceive the flicker. Probably worth considering, especially if you have a dog with epilepsy.
(Incandescents also flicker at 50/60Hz of course, but the thermal inertia of the filament makes this a lower amplitude flicker.)
If you are sensitive you can get really, really annoying blips of flicker even above 1khz - https://journals.sagepub.com/doi/10.1177/1477153512436367
They also flicker really badly if your power is not perfect, like you have a decent sized training rig on a different circut.
Incandescents are basically little light inductors and I would imagine the luminosity curve would be sinusoidal vs whatever hell a LED driver chip puts out.
I have a theory that they're bad for humans too. I think the same is true for computer screens too. Something about the flickering and the "unnatural" color spectrum messes with people's heads (anecdotal/subjective). Maybe our brains do extra processing work that detracts from other systems.
The newer phosphor-coated "filament" LED's also have this "inertia" which is nice. And no other electronics to fail also since they are just series-connected LED's.
The phosphors do have some inertia, but I'm not sure if it's really enough, since fluorescents have phosphor coatings too and those are notorious for noticeable flicker. Different kinds of coatings though, different thickness and quantities of phosphors, maybe different composition too. I don't know how comparable they really are.
Besides the epilepsy, what do you mean with "bad for dogs?"
Sidenote: My partner and me both "feel" the difference of cheap LEDs. Its not something we can pinpoint down, but it got way better with hue lights.
We live with multiple dogs and iam really curious. One of the dogs that we often had around had severe epilepsy that very strong medication was needed and the dog died anyways way to early around the age of 2. She had less sizures than in her original home when she was with us which ofcourse might be unrelated to the lighting. But your thought is interesting.
> Besides the epilepsy, what do you mean with "bad for dogs?"
Psychological or physiological unease at least, I assume this from the way rapidly flickering dying florescent lights make me feel.
When you notice flicker, your iris is trying to expand and contract at that rate to compensate. It was one of the things people were pointing fingers at for sick office syndrome, back when fluorescent tube lighting was popular. People, and I assume dogs, have different thresholds when this problem kicks in and flicker becomes noticeable.
I tried Hue lights last year but 50% of them had problems. Did you run into that too?
No issues but I bought my last one like 2022 and didn't need to replace any of them.
Bad LEDs flicker at twice the power supply frequency, so 120 hz which is very perceptible by most humans.
But also note that not all LED lights flicker.
Why don't LED drivers just use plain continuous DC with no PWM?
Sibling comments have no clue what they're talking about. I actually engineer these things.
The short answer is cost and heat. What you're describing is a linear constant current driver, which are the gold standard for flicker-free operation. Drawback is a much more complex circuit and a transistor burning off a ton of waste heat.
A constant current driver requires sensing the current across the LED, which involves sensitive analog circuitry. A PWM drive requires essentially nothing more than a FET tied directly to your microcontroller.
There are switch-mode constant current drivers, best of both worlds. Essentially a buck-boost converter in current mode instead of voltage mode. These are slightly more expensive, so they don't appear in consumer lighting products.
All that aside, the reality is that if your PWM frequency is high enough, it doesn't matter. Above several KHz it's imperceptible. The reason that this still isn't done universally is that it's a third of a cent more expensive to use a controller that can switch above 1KHz. All hail the glorious race to the capitalistic bottom.
At work I just finished up a constant current driver circuit. At home I'm building a custom lighting system with bespoke driver circuits. Despite having a CC driver I can pull off the shelf, I still chose 10KHz PWM. It's easier and more efficient, and neither you or I could tell the difference in the quality of the output light.
What about the IKEA light drivers? They claim to be flicker free.
Another optical engineer here.
I used to wonder WTF was so hard about LED lighting. One R, one G, one B, a shunting resistor and... and then I took a glance under the hood. Oh. Yeah, much dicier than heating up some tungsten and frosting the inside of the bulb.
(Yeah, inventing cheap blue LEDs was some serious heavy-lifting in itself, but that hurdle has been jumped.)
Dimming. And even without that, the "continuous DC" is usually provided by switch-mode power supplies that themselves have a PWM ripple. How much depends on the quality of the supply.
Since AC is pulsating you need to store some energy to get continuous DC, usually in a smoothing capacitor. And that capacitor is relatively big and when durable, then not cheap. And it requires some further complications (like avoid inrush current).
Cost.
> (at least usually).
Nope. Lots of people see the strobing. Its causes headaches if you focus on the lights.
There is a 15-30% difference between the groups at baseline (fig 8c-9c, 8d-9d), about the same magnitude as the claimed effect of the experimental condition.
I think the result would be much stronger if these baselines were comparable, so they show they have accounted for other variables like time of day and light history. I am also skeptical of any effect in the retina lasting 6 weeks, with no fading.
Consider that people are often exposed to much more infrared light outdoors, so "worked under a relatively dim incandescent lamp" is not a particularly novel stimulus. Imagine that any of these people spent time outdoors during the six weeks - thousands of times more infrared light there.
Indeed - these study results are fairly substantial if they can be independently reproduced by more studies at bigger scales.
The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications. Also, many less expensive LEDs flicker at the rate of the frequency supply of the current (ie 240 or 120 Hz). This is very annoying and related to the instantaneous response of LED vs the averaging effect of the alternating current through an actual glowing hot filament. It is interesting to read on the development of blue and white LED technology.
In the EU this was indeed done for energy efficiency/emissions. Incandescent bulbs were gradually banned from normal sale, starting with the most energy hungry (diffused 100W) and gradually expanding until only low-wattage and special-purpose bulbs were left. Special-purpose bulbs cover a large variety for everything where switching didn't make sense, like machine shops or historic buildings. LEDs aren't mandated per se, but they are the most attractive alternative. And because this all happened before brexit the UK has the same rules, unless they revised any of them post-brexit
For the most part this was a very positive step. Prices for LED bulbs plunged when they went from the "premium" energy-efficient alternative to the default option. But you also get a lot of crap on the market, and stuffing LEDs in form factors designed for incandescent bulbs makes good electrical and thermal design challenging. Even for those brands that actually try
> LEDs aren't mandated per se, but they are the most attractive alternative.
Yeah, basically what the EU did was to say: For X Watts of electricity at least X Lumen of light has to be produced. And this number was gradually increased. Since old school light bulbs are quite inefficient when it comes to producing light, they slowly had to be phased out.
> The push toward LED seems to be primarily for emission target related reasons
Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.
Some cheap LEDs do flicker (at 50 or 60 Hz). But that’s fairly easily solved. I don’t think I’ve noticed the flicker since some cheap bulbs I bought in 2014 or so.
"I don’t think I’ve noticed the flicker…"
Well… (Sorry, let me put my tinfoil hat on.) Yeah, well that noticed part is what is worrisome to me. I do worry that there is some effect on our brains even though we might not perceive the flicker.
As an analogy, I got into those supposedly audiophile "Class D" (or "Class T") amplifiers over a decade ago. Every day I turned on the music in my office and coded with the T-amp playing. I would have told you at the time that, indeed, it sounded amazing.
Some time later I built a tube amplifier (The Darling [2], in case anyone cares—I've since built perhaps a dozen more).
When I brought it into the office and swapped it out for the T-amp, the change was sublime but immediately noticeable. I hate to fall back on audiophile terminology but it's the best I have for the experience: I was suddenly aware of "listening fatigue" that had been a component of the T-amp. I hadn't even known it had been fatiguing until I heard the tube amp in its place for days on end.
With the loss of color fidelity and the flickering issue, I'm embarrassed to say that incandescent is starting to look good to me again.
I might, as an experiment, replace only those lights that we turn on in the evening when we are relaxing, reading.
[1] https://en.wikipedia.org/wiki/Class-T_amplifier
[2] https://www.diyaudio.com/community/threads/darling-1626-amp.... and https://imgur.com/gallery/oh-darling-tube-amplifier-Lq2Sx
If the LED has good DC conversion it should not flicker at all, the flow across the diode would be constant. Just buy good LEDs, incandescent light has many drawbacks.
Incandescent light has exactly one drawback, no more.
This is a really interesting comparison, but a flawed analogy. (I’m absolutely not challenging your preference for tube amps.)
LEDs clearly do not produce anything like the spectral energy of blackbody radiation (sunlight, incandescence bulbs), and many do flicker (although that’s a byproduct of individual designs, not the technology itself). This is easy to confirm with simple sensors. So it’s completely uncontroversial to say they don’t replicate “natural” light.
Pretty much all tube amp designs produce an output that is modified from the input signal. This is what makes them sound different and to plenty of personal opinions more enjoyable to listen to music on. But they are more like the “LED” side of the lighting example - they produce an output that is different from the “natural” aka original audio material.
> Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.
its the same thing. If it uses less electricity it both reduces the cost to you and reduces emissions from generating electricity.
I think most people would have switched over gradually anyway, but effectively banning incandescents speeded it up.
>Is this true? I’ve got LEDs in my house because they cost vastly less to run, and because I rarely have to replace the bulbs.
At least in EU is true. Citing from Wikipedia: "The 2005 Ecodesign directive covered energy-using products (EuP), which use, generate, transfer or measure energy, including consumer goods such as boilers, water heaters, computers, televisions, and industrial products such as transformers. The implementing measures focus on those products which have a high potential for reducing greenhouse gas emissions at low cost, through reduced energy demand."
https://en.wikipedia.org/wiki/Ecodesign_Directive
I have not found that LED bulbs last noticably longer than incandescents. I'm still replacing bulbs, and though I don't keep records it feels about the same.
LEDs are just terrible in every way except electrical consumption.
My first hue led is from around 2015 and is still working perfectly fine.
Every other low quality led I bought around that time or even later is long dead by now. I disagree
Even off-brand ones now are lasting longer than the ones 10 years ago. It used to be a problem, now I rarely change any bulbs.
Good LEDs in the right circumstances will last almost forever - unfortunately many LEDs on the shelf are trash. They often have small print about not using them in enclosed fixtures or sconces since their thermal management is atrocious and they will self-immolate if not in open air.
I've seen some overheat themselves even in open air!
If you buy cheap off-brands on Amazon that's what happens. The cheap ones have poor thermal management around the LED drivers, and the heat dissipated will eventually burn the drivers out, much sooner than is reasonable.
Hooray shitty capitalist incentives.
The non-cheap LED bulbs I've bought have all lasted years and years. I do have some cheap ones that are starting to fail, after just a year or so. (Problem with those is that it was really hard to find the correct bulb size and connector type, so my options were limited.)
It does seem an easy win for govts to easily conform.
I buy the ones that are suitable for dimmable switches (even tho I don't have dimmers) because there is discernible flicker with most other LED bulbs if you for eg wave your arm through the air or made a saccade. There is a certification (i think) for LED bulbs that are closer to sunlight in their emission spectrum
Look for high Ra or CRI value. Dont buy cheap LED lights, they last for far too long.
LED bulbs, even though cheaper in the long term, used to habe high enough shelf prices enough that most houdeholds wouldn’t have switched without a government push. Incandescents are literally banned now for most uses, while the economies of scale have helped drive LED prices down.
It costs 8x more to power an incandescent lamp than an equivalent LED lamp, the LED lamps pay for themselves very quickly.
It costs less to run because less energy is used; I'm pretty sure incandescent bulbs aren't emitting anything by themself! "The push" is from the government, perhaps consumer demand is "the pull".
They do emit a lot of heat!
Almost all the energy consumed by appliances in your home gets ultimately converted into heat. For example, the picture on your TV is made from emitted light rays that are absorbed by various solid objects in your home and heats them up. Same for the sounds from your speakers. Your washing machine spins water and clothes around, which makes both the water+clothes and the body of the washing machine to heat up due to friction.
A counter example is a water pump, which converts electricity into gravitational potential energy of the water as it flows upwards.
Not sure about the point of your comment. Ok, doing work generates heat. But if the primary goal is to generate light, not heat, then incandescent bulbs are terrible at their job.
which is not that bad if you want to warm your room a bit. The heat is not wasted, but added to the room. We use 250 watts to warm under the coffee tables. These are infrared-coated incandescent bulbs
What if it's a hot summer night? :)
My point was about efficiency of the generation. You want the light, you don't necessarily want the heat.
Save heating for the (efficient) heat pump.
The flickering is solely a result of cost cutting in the power supplies of these LED lights. The problem is totally solvable with a constant current switching power supply. But the filtering circuitry adds cost.
The problem is that consumers usually cannot know this about a particular light (or a lot more) at the point of purchase, so even if you are willing to pay a premium for this you cannot.
I would pay a premium for longer life, and at least in some cases (e.g. lights I read by) for better quality. How do I do so? I would love to be pointed at sources of better ones (in the UK).
In the EU, lights have to be sold with a mandatory energy efficiency label. A lesser-known component of this is that this label includes a link to a standardised datasheet, which includes things like flicker metrics, CRI, chromaticity, and a measurement of the spectrum.
It doesn't fully quantify the light, but it's good enough to distinguish trash or even passable lights from actually good ones.
tl;dr: Just buy Philips UltraEfficient (I think these are roughly equivalent to the infamous "Dubai Bulbs"[1]) or Ultra Definition bulbs. They cost a little bit more but will probably pay for themselves over the years.
Buy name brands with a history of putting out decent bulbs instead of the Amazon alphabetsoup brands that won't be around in 5 years (although TBF some of my cheap BogAo bulbs are still going strong after 8 years). You can get a good feel for the light's "quality" by looking at the CRI and color temperature.
For CRI, anything 90+ is good.
For temperature, IMO around 3000k is the sweet spot. go higher if you want sterile operating room vibes or lower if you want super yellow/orange cozy hobbit hole vibes.
[1]: https://hackaday.com/2021/01/17/leds-from-dubai-the-royal-li...
> The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications.
Can you even buy them without buying new old stock? In the US they're banned and there's zero production.
I recall there was a guy in the EU who tried to get around the regulations by selling "heat bulbs" that were exactly the same as traditional incandescent bulbs but marketed as a heat source, but I think he was slapped down.
At least in Germany you can still fairly easily get 20W incandescent lamps. Sold as lamps for fridges and ovens, but they are available with standard sockets.
If you look around a bit you can also get 60W or 100W lamps, sold as "industrial lamps" or "extreme temperature lamps", labeled as unsuitable for household use. But those are specialty lamps that you won't find in your local supermarket. Not sure if those are new old stock or imported
Certain size/watt combos are still available for things like appliances and nightlights, but I think that includes 20W E26/A-something bulbs, and the bulbs for plug-in night lights. I can still find them on the Home Depot and some other places. No idea about quality but I still prefer how they look. There are so many other horrible energy efficiency problems with heating my home that the inefficiency of a few incandescents in key places doesn't bother me in comparison to the enjoyment I get from the nice light.
In the US they've even banned selling new old stock. I believe that was a recent change within the last few years.
If I were able to see the flicker of mains supplied LED lighting (which I cannot), then I would be very tempted to install low-voltage DC LED lighting, which presumably does not flicker.
An AC/DC power converter works the same, either built into the bulb or in a separate unit. But yes, a separate power converter is almost certainly going to do a much better job of removing the 50/60Hz voltage drop. Not sure if it would be cheaper, given the economies of scale on AC bulb manufacture. Higher quality AC bulbs may come out ahead for flicker free lighting.
It only doesn't flicker if there's no power driving circuitry - eg just LEDs and a resistor.
Otherwise, if there is a power IC present, there is flicker, though fast enough for most humans to not perceive normally (you can still check it by waving your hand in front of the light and seeing the strobed afterimage.)
That's not strictly true. The very simplest of DC LED drivers flicker, such as the classic single-transistor battery saver circuit, but a slightly more complex DC LED driver circuit will not. One of the best ways to drive an LED is with a constant current source, which typically involves putting an inductor in series with the LED and switching the supply to that at a reasonably high frequency, which would mean the LED does not flicker at all.
If it's hooked directly to AC power, isn't there by definition a flicker? With a power IC, a poorly implemented power circuit will also visibly flicker. With high enough rate and the right power characteristics it should not be noticeable. Do you notice flicker in a quality phone or monitor screen?
Yes! And this after image is distracting.
Wouldn't the supply usually be either 50hz or 60hz depending in the country?
Yes, OP incorrectly quoted voltage rather than frequency.
Very interesting. I've always thought that there was something a bit "off" about LED torches and car headlamps; the brightness is there, but something about the light just doesn't seem to illuminate as well as an old dim incandescent or even fluorescent tube.
It's usually the Color Rendering Index (the spectrum of frequencies that the light puts out). Incandescent bulbs more of less mimic that of the Sun, they are "black body radiators". Cheap LEDs tend to be missing a lot of the red spectrum.
However, you can get LEDs that do this well. Look for one with a "CRI" of 95% or higher.
The CRI is an imperfect metric, I watch for both CRI and R9, both should be high.
There's a massive difference between the 2600K of regular incandescent bulbs, and the 6000K of sunlight. That's why hollywood used HMIs until they migrated to LED.
For professional applications there are sulfur plasma lamps which have a continuous spectrum at high efficiency. Unfortunately they aren't economical below about 1000 watts which is impractical for many applications.
The technology basically works by continuously microwaving (think oven) a small amount of sulfur gas. The development of solid-state microwave emitters — most microwave generation is still done with vacuum tubes — might help miniaturize the devices. However, it's hard to beat the simplicity of an LED.
wow - had no idea these things existed, fascinating.
There is, but most humans are used to the spectral pattern of black body radiators at all color temperatures. Be that sunlight at higher temperatues or fires / candlelight at lower temperatures.
Regular exposure to fire/candlelight has only existed for a hundredthousand years, while mitochondria have existed almost unchanged for millions of years.
So even that assumption would require further study.
They're saying that the visual performance is indirectly affected by invisible wavelengths somehow. Not that you can see the difference between two types.
They are saying that, and most real world LED lighting uses very cheap diodes, like, 99.9999% of them, which create very poor colour compared with incandescent bulbs, which create perfect colour representation.
It's a big thing and you can buy LEDs which produce a better colour range, but they're much more expensive and not as energy efficient, because creating bold reds costs hard energy that no diode trick will ever get around that.
>They are saying that, and most real world LED lighting uses very cheap diodes, like, 99.9999% of them, which create very poor colour compared with incandescent bulbs, which create perfect colour representation.
Have you actually read the study? It's about infrared and has nothing to do with color rendering and visible spectrum. They're vaguely speculating about some mitochondrial mechanism of action not related to vision at all.
That's the interesting thing about this study. A lot of people here are speculating around explanations connected to metamerism, but the control (Figs 7 and 9) partly rules that out.
It's a poorly controlled experiment.
https://news.ycombinator.com/item?id=46764382
I get that they're more efficient in some sense, but man the LED streetlights and other big lamps are so irritating and make things like like such ass compared to mercury vapor or even sodium lights.
True. Yet, somehow more and more cities install them blindly because efficiency. I remember when I moved to Odense Denmark in 2013 - they had LED street lights all over the place. I thought - this is the future compared to my uderdeveloped post soviet Latvia. And yet, I remeber when I moved back, streets at night looked so yellow because the city still relied on sodium lights. And my eyes felt much more comfortable. At the time I wrote it off to nostalgia or something, and here we are.
Even a colour filter would help with the harshness.
True, but that lowers the energy efficiency.
For LED lamps, the color must be controlled at the emission source, not by filtering, i.e. by using an adequate combination of different conversion phosphors, to ensure a neutral white with a quasi-continuous spectrum, instead of a bluish white with great narrow peaks in its spectrum.
Unfortunately, the phosphors for the latter variant are much cheaper than for the former, so the lamp vendors have the incentive to make the lamps as bad as possible.
By must, is that only for energy efficiency?
I ask only because I was retrofitting some navigation lights on a sailboat - and you can’t just upgrade the original incandescent bulbs with LEDs (or aren’t supposed to).
You are either supposed to get a special LED (backing up what you’re saying) or there are some new red/green enclosures that are differently treated / tinted to then put a “white” led into.
But I am so far from an expert on that, I may be completely misunderstanding.
When you use any kind of filter for a lamp, that stops a part of the light produced by the lamp, the part that has an undesired color.
So, at the same electric power consumption you have less light, or you can compensate by using a more powerful lamp, to get the same amount of light even with a filter. In both cases the energy efficiency becomes worse, i.e. the expenses for electric power are greater per output light.
On the other hand, when the manufacturer of the lamp controls inside the lamp the conversion of the light produced by the LED through fluorescence into the light that exits the lamp, there are chances to obtain a desired color and a certain shape of the emission spectrum by wasting less light than with external filters.
Filtering can correct a lamp color that is not the color that you want, but it cannot fill gaps in the emission spectrum of the lamp.
Cheap white LED lamps not only may have a too bluish color (or in some cases a too yellowish color), but their emission spectra may have gaps, so if a natural object from the environment happens to have a color that falls in a gap of the LED lamp spectrum, it will appear much darker than in daylight. This can cause orientation problems or difficulties in identifying certain things.
Where LEDs are used for signalling, not for lighting, so pure colors are desirable, much less problems exist, so e.g. the replacement in the red or yellow signal lights of cars, of the old incandescent lamps with color filters, with monochromatic LEDs without color filters, has posed no difficulties.
Yes lots of them use cheap LEDs with poor CRI, high color temperature, and a huge blue spike in the spectrum. All of that leads to a very bright looking light that also doesn't let you see detail very well.
Just to point to anybody that comes here directly, the article has no relation at all with perceived illumination, color fidelity, or anything else people complain about leds.
It's an interesting niche topic that you may want your working place to notice if you work indoors.
I’ve always been mildly bothered by the LED lighting in my home, as if it’s simultaneously bright but not illuminating. In simple consumer terms, if I wanted to shop for a variant that more closely replicated incandescent lighting, what exactly am I looking for on the packaging? Or does this not exist?
What's available depends on the form factor, but there are some manufacturers that offer some choice in the 2700k 90+cri space nowadays.
It’s called SSI, spectral similarity index. SSI is specified for a color temperature, eg 3200 or 5600. 100 is identical to tungsten or sunlight. Values above 85 are good.
In the UK I've not been able to find high wattage (10-20W) LED lightbulbs with high CRI, some don't even mention it in listings, let alone SSI, which I have never seen.
Where are you seeing these? Is this industrial/commercial suppliers?
It’s rare, unfortunately, and usually not in the typical bulb formats. Here’s one for example with an SSI of 89 for tungsten: https://amarancreators.com/products/amaran-100x-s?Title=Defa...
Phillips, try searching for EyeComfort. I think all of their premium bulbs have 80+ Ra.
GE Relax is my preference, with 93 Ra. A good all-around bulb.
https://www.housebeautiful.com/shopping/a31139492/ge-relax-l...
They look good, but cannot find a listings with all the details though to know exactly what I will get if I buy them.
It is a good start and I know know its wroth looking, so think you.
I buy the "warm" light LEDs, which look (to my eye) closer to incandescents.
Standard LEDs bulbs are bright white, almost bluish, and yes "bright but not illuminating" describes them well. I feel many modern car headlights have the same issue.
The human eye doesn't focus the blue end of the spectrum very well.
There is no such thing as a “standard LED lamp”. LED lamps come in a huge variety of shapes, various bases, power usage/lumen output, color rendering index, and color temperature.
Lots of companies sell cheap crappy A19 E26 base 5000K lamps, that doesn’t make them the ‘standard’.
Bulbs that test well on spectrum and flicker tests, Phillips Ultra Definition is a good one I believe.
https://www.thesmarthomehookup.com/25-soft-white-led-light-b...
Nothing on the box really means anything, so many bulbs claim high CRI and everything but in reality have terrible spectrum. So you can only go off of actual real life testing from a third party.
Ra value is (often) written on the package, go for 95+, it’s a bit hard to find but the difference is real. I Do not buy under 90.
No mention of CRI which seems kind of odd. LEDs for lighting are increasingly graded by how natural their emission spectrum is. Older lights are quite bad, newer ones sacrifice a tiny bit of performance for more uniform spectrum.
They use rf numbers, which is a newer standard, so that's probably good.
However, the experimental group (extra light sources) got rf 91 bulbs, and the control ("LED lighting") got rf 85 bulbs.
The two scales are not exactly comparable, but they both max out at 100. The only source I could find that discusses both says that > 90 CRI is "excellent" and just below that is "very good". It says > 85 rf is "very good", which tells me it's comparable to a mid-80's CRI bulb.
If I accidentally buy a mid-80 CRI bulb, I either return it to the store, or just throw it away.
So, I'd say this study's experimental setup doesn't support any useful conclusions. They showed that so-painfully-bad-California-won't-subsidize-them LEDs are worse than passable LEDs with supplementation from another light source.
The passable LEDs in the study are probably comparable to the cheap ones at our local hardware store, but worse than the ones that cost $10-20 on amazon ten years ago.
This would have been much more interesting if they'd compared high-end LEDs with and without supplementation, and found a difference. (And by "high-end", I mean "still much cheaper then the electricity they save")
I think CRI is not important here as thats a measure in the visual spectrum. The paper talks about all the missing wavelength outside of the visual spectrum.
CRI is a pretty bad rating system. They are showing the full spectrum graphs which is what you'd want anyway. Spectral Similarity Index (SSI) is the better number
Sure, but I don't see them mention what they're actually using for LEDs at all. They mention a "colour fidelity index" but I'd expect a manufacturer part number or something so I can pull the datasheet.
Funny enough, the best evidence for this study is that they should probably move somewhere with more sunlight if they can't spell "color" right... /s
They are not using an index much, they are showing you actual spectral graphs. Ask an AI to understand how that is the actual info you'd want.
Is "ask an AI" the new rtfm?
What is the relationship between CRI and how broad (or narrow) the spectrum output by the LED is? Is CRI automatically better for broader-spectrum LEDs? Or is that too simplistic?
Slightly overly simplistic because the broader-spectrum LEDs could be broad-but-spikey for their output, resulting in light that is broad spectrum, but has a bad CRI (because it's eg really blue).
Out of curiosity:
a) How do Philips Hue bulbs stack up?
b) Did Philips update them generationally and assuming they are decent now, how recently?
It was known among MTB riders who ride at night sometimes: typical XM-L T6 Chinese headlights were unusable in the forest when you move fast. Good diodes (like Nichia 219B) worked. And XM-L was dominant even in very expensive «brandnamed» lights for many years (you could buy Aliexpress headlight for $20, you could bu "Italian" lamp for $250, result is the same)
I'm not in this scene anymore for many years, but when I was, I built my one lamp from custom light engine (essentially round PCB with DC-DC current limiting schematics an LEDs) with 3x219B, Chinese body and CARCLO TIR Optics...
Good times.
> In humans a single 3 min 670 nm exposure improves colour vision within 3 h, which is sustained for almost a week
That seems remarkable and almost too good to be true?
Seems like this is only relevant for people who don't go outside for weeks at a time? This article has a strangely "pro-long-wavelength" tone, yet sunlight also exposes you to UV frequencies that are so harmful according to this paper.
Was just discussing last week with a colleague how for the same 'lumen' there was such a dramatic difference between led and incandescent bulbs for ease of reading paper books.
Which one of the two was better for it?
Incandescent, by miles. Not even in the same ballpark. Even just candlelight beats led.
There are very great differences in light quality between various kinds of LED lamps.
You may have various LED lamps, all of which appear to have the same white color, but their spectra are very different. Those with narrow spectral peaks are very bad lighting sources, while those with wide spectral peaks, achieved by using multiple kinds of conversion phosphors, are much better lighting sources.
With the best LED lamps, there is not much difference in comparison with incandescent lamps. While incandescent lamps are best from the point of view of their continuous spectrum, their yellow light strongly modifies the perceived colors. While bluish white LEDs (e.g. of 6500 K color temperature) are also bad, neutral white LEDs (e.g. 5000 K or 5500 K) provide much better color perception than incandescent lamps.
For home lighting I prefer a white that is only very slightly yellowish, i.e. 4000 K lamps, instead of LED lamps with a higher color temperature or of incandescent lamps, which are so obviously yellow that no clothes have the same color as in daylight.
The best quality of lighting can be achieved by incandescent lamps in conjunction with frequency-selective filters, which modify their spectra to resemble the spectra of a blackbody with a higher temperature, like the Sun.
Such filtered incandescent lamps were used a very long time ago, to provide lighting for color photography, movies and television (e.g. for the original white point of NTSC), but they were abandoned due to high cost and due to an exceedingly low energy efficiency.
As I have mentioned in another comment, filtered incandescent lamps might see a revival, but implemented with very different technologies than those used a century ago.
To put it bluntly, it could also be that your LED light sources are low-CRI junk.
I use 90CRI LED lights where I study. They are Philips' non-flickering, dimmable, High CRI bulbs, yet my classic 25W halogen table lamp still provides a far better reading experience. The spiky spectra of LED lights are not comfortable for eyes as a full-spectra incandescent light, let it be classic or halogen.
90CRI isn't good enough to replicate an incandescent bulb in my experience. Something in the high 90's can be much better (but admittedly hard to find). And of course you may want to match your preferred color temperature too.
Actually, this is the best I was able to find. The prices increase almost exponentially when you try to go to higher end of anything, and I was not in a mood for digging whole city and the internet for a single bulb. A Philips' 90CRI bulb is already a great upgrade from an 80CRI bulb, so I ran with what I was able to find in a pragmatic time frame.
For reading black & white text, incandescent lamps are perfectly fine.
However, if your book has color illustrations, a high-quality neutral-white LED lamp is better than any unfiltered incandescent lamp.
A standard white illuminant with filtered incandescent lamps would be even better, but such lamps, as they were made a century ago, were extremely good space heaters, which may prevent their use for reading a book.
The OSRAM halogen lamp I use has special filters, and looks greenish when it's turned off, so it might not be a "brute force, let everything through", 25¢ halogen lamp. The bad thing is it's not being produced anymore, but I have a couple of spares.
I went through university with the same lamp/bulb, so that combo doesn't create the unwanted reflections much. Also, I still print everything in color, because a good color choice still boosts understandability of the material at hand.
One of the authors of this paper did a pretty long podcast with Huberman about this topic:
https://www.hubermanlab.com/episode/red-light-to-improve-met...
The show notes have links to quite a few more papers. I have no idea if this is good science but this is not just a one off paper.
It's junk science.
https://news.ycombinator.com/item?id=46764382
It’s a shame that grift claims everything.. once upon a time, Huberman was a serious person but he’s now just Joe Rogan with an advanced degree - platforming all sorts of bullshit for a check. At least there are other sources listed though so thanks for those.
It should be noted that even if we assume that the conclusion of this study is correct, i.e. that artificial lighting should have a wide spectrum including near-infrared light, that does not mean that returning to classic incandescent lamps is the right solution for this problem.
The incandescent lamps with tungsten filaments have a much lower temperature than the Sun, thus much more energy is radiated in infrared than needed.
There was about a year or two ago a discussion about a very interesting research paper that reported results from testing an improved kind of incandescent lamp, with energy efficiency and lifetime comparable to the LED lamps.
The high energy efficiency was achieved by enclosing the lamp in a reflecting surface, which prevented energy loss by radiation, except for a window that let light out, which was frequency-selective, so only visible light got out, while infrared stayed inside. The lamp used a carbon filament in an environment that prevented the evaporation of the filament.
With such a lamp, one can make a tradeoff between energy efficiency and the content of healthy near infrared light, by a judicious choice of the frequency cutoff for the window through which light exits the lamp.
Even with enough near-infrared light, the efficiency should be a few times higher than for classic incandescent lamps, though not as good as for LED lamps. Presumably, one could reach an efficiency similar to that of the compact fluorescent lamps (which was about half of that of LED lamps), for such an incandescent lamp that also provides near-infrared light.
How does enclosing the lamp in reflective material help with the energy efficiency? Isn't the infrared radiation emitted anyway? Doesn't that make the lamp overheat?
If the reflective material is ideal, by definition no infrared or other radiation is emitted.
Perhaps I was not clear, but the reflective surface was the interior surface, so it reflected any light, visible or infrared, back towards the emitting filament, while the front window reflected only the infrared, while transmitting the visible light.
The lamp does not overheat, because the filament is kept at a constant temperature, the same as in a classic incandescent lamp. The difference is that you need a much lower electrical current through it for maintaining the temperature, because most of the heat is not lost away, like in a classic lamp. The fact that you need a much smaller electrical current for the same temperature is the source of the greater energy efficiency.
Only if you had used the same electrical current as in a classic lamp, the lamp would have overheated and the filament destroyed, but you have no reason to do that, like you also do not want to use in a classic lamp a current higher than nominal, which would overheat and destroy it.
Someone please tell the Australian government now that we've essentially banned other forms of lighting. (except fluorescent)
You can buy full spectrum LED lights (99 CRI, or grow lamps)
The article uses LED as synonym for typical LED lightning.
How is "full spectrum" defined in this case? Visible spectrum is not the subject of the paper, as they care about infrared.
Also even limited to visible spectrum, I have not seen any 99 CRI bulbs. The highest one I have ever found are the 98 CRI by YujiLED, but you pay around $35 for a single bulb. It is absolutely not "easy" to get flicker-free high CRI bulbs, let alone ones that cover the infrared range.
Phillips, GE, Cree, and others sell high-CRI bulbs.
10 years ago you had to work to find high CRI bulbs but could still find Cree bulbs pretty easily. Now you can get high CRI bulbs at the grocery store.
High CRI bulbs generally have low or no flicker because high CRI is toward the premium end of the market.
IR emission is not a "feature", it's a bug.
Almost all of the bulbs you can find at a hardware store (let alone grocery store) exhibit terrible 120hz flicker. I know because I've literally tried every single one. Also it's not hard to get "high" (~90-94) CRI while nonetheless having terrible deep reds.
Out of the manufacturers you listed, only Philips Ultra Definition (95 CRI, R9 90) have low flicker and good R9. Unfortunately they are poorly made and I have to keep buying new packs each year but it's more cost effective than Yuji for lesser used areas.
Also the claim from TFA is that NIR component improves visual performance (and I've read elsewhere that NIR also has health benefits).
How about Phillips flicker-free "warm glow" bulbs? I honestly have a hard time believing that they flicker because I can literally unscrew the bulb and watch it dim gradually over the course of a second. Which indicates to me that there's a capacitor in front of the LED drivers smoothing the current out. (Which I guess is required to be compatible with triac dimmers anyway.)
Never tried those, but speaking about flicker, some LED lamps flicker not because of the mains frequency (50/60 Hz depending on where you live) but because of their internal switching power supplies.
It's mostly a crapshoot even within the same model line. Even under "Philips UltraDefinition" some styles have high flicker while others don't. I'm not sure being dimmable is any guarantee of smoothing quality, in fact dimming is usually implemented with PWM as I understand so the easy solution to avoid flicker of chucking a smoothing capacitor on there might make it harder to implement dimming. (To dim properly without noticeable I think you'd have to PWM in the kHz range. Even cheap CFLs necessarily had the technology to operate on this frequency, for some reason it seems rare for LEDs to do it.)
https://optimizeyourbiology.com/light-bulb-database
They are specifically advertised to be compatible with old dimmers. I'm not an EE but old dimmers are implemented with triac which necessitates some juicy capacitors to hold the charge. Of course they could reintroduce flicker later in the pipeline for some reason, but why would they?
Oh that's interesting, LEDs used to require special dimmers. Maybe they have changed things with the latest generation of bulbs.
Huh, through experience with (mostly non-premium) LED bulbs, I've learned to interpret "gradually dims over the course of a second" an an early indicator of imminent bulb failure.
Have you tried LEDVance?
> IR emission is not a "feature", it's a bug.
If you look at energy efficiency, it totally is. But the whole point in the discussion is that IR _might_ (according to the paper) have biological relevance.
Specialized stores or online. If enough people start buying them, they become popular and cheaper.
https://www.waveformlighting.com/ sell 99 CRI LEDs. They're in strip form not bulb form, and they're definitely expensive, but they are available.
Call me when there's lights with a cri r9 of 99
You can't buy heat lamps? They are even more infrared and last longer.
Also LED lighting can have infrared, have a significantly more smoother spectrum curve and still last +20k hours without burnout. The cheaper bulb spectra that they show is a blue led + phosphor coating, but there are infrared LEDs, UV leds, and more. You can make quite the convincing sun simulation, even better than any incandescent bulb, but there is almost no demand for UV + Infrared super full spectrum lighting unfortunately. Only movie & theater lights come close.
>LED lighting can have infrared, have a significantly more smoother spectrum curve and still last +20k hours without burnout
Do you have a link to a bulb that you can purchase meeting all these criteria? The only one I'm aware of was this obscure "StarLike" that was never actually sold in bulk. LEDs can be made good in theory sure, but in practice they are all terrible in light quality compared to a standard incandescent.
https://budgetlightforum.com/t/sunlike-vs-starlike/64155/7
You would need to see the spectra of the various LEDs available and create a mix along with phosphor mixes. The closest thing is something like a BLAIR-CG light engine from aputure where they have something like 9 different colors of LEDs that mix together, but they don't put any infrared leds in them because they are for movies and they don't put any UVB or proper UVA leds. But there are infrared, UVA & UVB LEDs that you could apply the same kind of engineering principle to make something that closely follows the sun spectra.
No, you can't buy them as bulbs. The closest thing is those red light therapy panels that include them.
Actually I looked again at YujiLED offerings, and they now have a standard A19 bulb that outputs NIR.
https://store.yujiintl.com/collections/high-cri-led-bulbs/pr...
You're paying through the nose though, but it finally exists now.
Typical electricity rates in Australia are up to 40c/kWh or so.
Do you really think $5 AUD per month per bulb that you’re running 8 hours a day is worth it for better spectrum quality?
Are we also going to ban powerful computers since they use lots of power?
There are efficiency standards and laws for large appliances.
This isn’t some kind of controversial subject. Ensuring home appliances don’t overconsume energy is beneficial for everyone in society.
You don’t want to have brownouts, blackouts, or run out of heating gas/oil in the winter.
You bring up the idea of regulating computer equipment power efficiency as if it’s crazy talk but it’s a real thing in concept. Governments do offer guidance and sometimes regulate computer efficiency. They have efficiency standards (e.g. Energy Star) as well as relying on industry standards (e.g. “80 Plus”).
Take a look at your computer monitor or TV box and it probably has an energy star logo somewhere if you live in the US.
The US federal government and other state and local agencies will not buy computer products that aren’t energy star compliant, and encourages businesses and individual to follow similar standards. Other countries might regulate further than these (dis)incentives.
https://www.energy.gov/femp/purchasing-energy-efficient-comp...
And if you bring up data centers, those are considered productive industry that has its own regulations different than home regulations. Plenty of things legal in industrial series aren’t legal in your house.
High-powered computers are a niche issue, which means on a society level there's little benefit to restricting them.
Lightbulbs on the other hand affect all of society, so they've got a much larger impact to the overall CO2 budget.
Additionally, the average person uses a laptop or mobile devices, all of which use less power than even a single typical incandescent bulb (and people usually have many lightbulbs).
Replacing incandescent bulbs with LEDs saves a lot of CO2 at basically zero cost, while getting rid of computers saves less CO2 for a much larger economic impact.
And even the effect described by this article has to be looked at in context, considering most of the light people experience in a day — and have experienced for the since homo sapiens existed — is natural sunlight, even in northern Europe during the winter (that's why EU law mandates windows with sunlight in every office, apartment, bedroom, etc.)
Sad to say, but concerning the PC, seems we're moving in that direction pretty fast.
I hope they don’t come for my 386 with 14” CRT
I find it a little strange that there is no real discussion of limitations in this paper. They mention the limitations of something they cite, but nothing about the data they themselves collected or the conclusions they draw from it
https://news.ycombinator.com/item?id=46764382
I've been using incandescent more often. All my vanity lights are 40w appliance bulbs now. The difference at night is remarkable. The LED is just too much even at 2700k. I still prefer LED for high power situations like br30/40 can lights.
I found some interesting tidbit about this bigger issue. And I want to share how to more easily check it.
We many times see some people reporting that they clearly see lower quality LED light flicker and is really distracting to them and even causes them headaches.
Now, I didn't see this until recently (unless in failing lights) in the right conditions. If the light is very, very dim: For instance, only 1 light on in the night, and you are in a division far away from the light so that it's extremely dim. There, I could finally really see it flicker.
I've replaced that light for a better one and the effect went away.
There are some full spectrum led lights, they just cost over $100 a piece. And they might get banned in the future for not being energy efficient enough.
Scientific Reports is a junk journal fyi. Not conclusive, but indicative.
Despite saying the visible flux component is "small" and that the tungsten lamps "were not expected to [be used] as task lamps," Figure 6 (a) and (c) shows... desk lamps right at the work stations like task lamps! Not only is this experimentally unblinded, but the visible light immediately in front of the test subjects is noticeably brighter and warmer. The effect could simply be due to reduced eye strain.
What would James Randi do? "Extraordinary claims require extraordinary proof," and unfortunately this isn't it.
This would be more interesting if they add a visible light filter on the lamps so they only emit infrared radiation, and have an identical double-blind control with a 60 watt heater bulb so it emits no SWIR but the same radiant heat (which could confound and/or unblind).
In EU, the ROHS directive forbids even more types of lightbulbs, beside incandescent:
Ban on all fluorescent tubes (T5 and T8 lamps) from August 24, 2023
Ban on all CFL lamps from February 24, 2023
Extension of the exemption granted to HPD lamps from 3 to 5 years
Extension of the exemption for special purpose lamps from 3 to 5 years
This should also be true for TL lights. Which kinda contradicts common sense seeing that those are used all over the place in offices, kitchens, and hospitals, makes me think this paper is bogus.
I don't think that this is the reason.
Yes, there is something obviously wrong with most LED lights, but it isn't too much of short wavelength light, but on the contrary. It's the near absence of cyan light in most LEDs. Our eyes are by far the most sensitive to it, the majority of receptors in the eye are sensitive to it, and we may focus primarily on it (focus differs for different wavelengths). This is how you get the feeling of something being wrong with your vision as you for example walk into a mall, and so on.
If anything, higher temperature lights seem to make it better, not worse, but the problem will persist as long as the cyan hole stays there.
Sensitivity peak for humans is in cyan (~510nm) only for low-light conditions (night vision / rod cells). In daylight (cone cells) it's green-yellow (555nm). https://www.giangrandi.ch/optics/eye/eye.shtml
Here you can see that cones only extend to 2° from the center. I think it's illegal to drive with less than 20°FoV.
https://www.google.com/search?client=ms-android-samsung-rvo1...
>The eye behaves differently in high or low light conditions: in daylight, for brightness levels above 3 cd/m2 the vision is mainly done by the centre of the retina, we can see colors and the maximum sensitivity is at 555 nm (in the green region). This type of vision is called photopic vision.
That's completely impossible, you would have severe tunnel vision in daylight, if it was true.
There has never been any real evidence that rods stop working in daylight.
wouldn't this be a good thing? I prefer my circadian cycles not to be disturbed by artificial lights and if i am reading this right, it is what happens with led lights. this would be different of course if i had no access to natural lights. glad to be corrected :)
ever since they replaced streetlamps with led (like a decade ago?) I can't see anything anymore before dawn
there may be more light (photons) but their spectrum is too limited for my eyes to see like halogen, etc.
I still only use compact florescent in my home, led is useless to me
The authors, bless their hearts, suggest that running halogen lamps at lower-than-rated voltages might be a good idea.
> If this is done with a halogen bulb, which is a type of incandescent tungsten bulb, the filament lasts for a longer period as evaporated tungsten is redeposited on the filament rather than blackening the bulb glass. Hence, using a halogen bulb at lower voltage is a realistic alternative in terms of health and energy consumption.
Unfortunately, as I understand it, the redepositing action only occurs at high temperatures.. It's a chemistry thing. I have been led to believe that running halogens at low voltages will cause the bulb glass to blacken sooner. See https://en.wikipedia.org/wiki/Halogen_lamp#Effect_of_voltage...
Also, LED strobes to dim. Which is unpleasant.
I hate the LED street lamps so much. I can tell they've got a really spiky and unnatural spectrum, unlike the HPS lights, not to mention that they're white or bright yellow...
I miss the orange glow of sodium lamps that characterised cold dark and foggy english winter nights.
Yup.
Even to this day when I'm on the bus on the highway it's so relaxing and comforting to ride through the orange lights.. then the bright white ones come through and it's almost like instant anxiety that kicks in
I have incandescent light bulbs at home I have to pretty much smuggle from China. It's amazing how we're replaying the asbestos playbook a century later. Only this time it's government mandated.
where do you purchase yours out of curiosity? My incandescent light bulb dealer on Ebay stopped selling them...
> It's amazing how we're replaying the asbestos playbook a century later
Can you elaborate?
Asbestos was pushed as a magical solution to problems of fire in homes without paying attention to the health effects. It took 80 years for the obvious to become law.
Leds are pushed as a solution to energy consumption by humans without paying any attention to the health effects. Hopefully it will be less than 80 years of cancers and metabolic disruption before the obvious is done.
But this time the regulation was captured pre-emptively, to the point that following best scientific advice for your health is illegal is most of the developed world.
LEDs being ugly or causing eyestrain is one thing. But cancer? There's very little chance that LED lighting causes cancer. We don't have a plausible mechanism for that.
There are no white LEDs. Just blue LEDs with coatings that convert a fraction of blue/violet light into lower energy colours. They work the same way that fluorescent light do.
This means that LEDs produce a much higher amount of blue light that incandescents: https://www.researchgate.net/figure/Spectrum-of-a-white-LED-...
Blue/violet light is known to cause cancer for a century now: https://www.nature.com/articles/s41416-020-01231-7
The linked Nature article basically says: there’s no clear evidence either way.
> But this time the regulation was captured pre-emptively, to the point that following best scientific advice for your health is illegal is most of the developed world.
Please cite your sources then. And no the other article you linked is not proving your claim
There's a mostly-unsubstantiated-by-data belief that LED lighting can cause health problems by some combination of flickering and narrow color spectrum.
There's a mostly-unsubstantiated-by-data belief that LED lighting can NOT cause health problems by some combination of flickering and narrow color spectrum.
Do you have evidence that this rock doesn't keep tigers away?
I guess you know better than the scientist studying it: https://www.sciencedirect.com/science/article/pii/S004896972...
Where does this article mention LED lights vs other types of artificial light-at-night? What I could find regarding light color:
> However, most studies relied on satellite-images with a very low resolution (1 to 5 km, from the Defense Meteorological Program [DMSP]) and without information on color of light
> noted that data quality suffered from many limitations due to the types of satellite images used and the focus in the vast majority on visual light levels only rather than considering the circadian-relevant blue light component, among others. Future studies should consider improved satellite-based ALAN technologies with improved resolution and information on spectral bands and apply these technologies to a variety of cancer sites to yield better estimates for the potential risks between ALAN and cancer.
So nothing conclusive about LED being bad for your health (vs other types of light).
It assumes basic knowledge of the spectrum of various light sources. All white LEDs have a spike in the blue spectrum that incandescents don't: https://www.researchgate.net/figure/Spectrum-of-a-white-LED-...
You're playing so defensive (for LEDs) wonder why - just to argue? If one uses the same logic - does anybody states that LED are GOOD for the health? What the lack of such statements means - they're bad, or have no effect? At the end - is it your business at all if I want to use incandescent lights, or CFLs, because I find them more suitable for my personal needs in MY home?
Maybe it causes eyestrain. It's unlikely to cause cancer. It reduces energy use, which reduces smog, which reduces cancer.
No I just refute a claim on which the provided source does not prove or indicate in any way. I'm not arguing LED to be better or worse, I'm just looking at a proof of some kind to what is argued.
But it seems like it's too much to ask? I should just accept whatever comments I read without any critical thinking?
Looks to me that _you_ conclude it's related to LED, I couldn't find that stated in the abstract, it might just be related to a general increase of artificial lightening, regardless of the source.
Per your link:
>The primary meta-analysis of indoor ALAN and breast cancer risk suggested an association, but it was not statistically significant.
That said, I'm actually sympathetic to the idea, and personally use incandescent lights. I just don't have any hard evidence to back it up (yet).
I’m guessing the Russian theory that asbestos is totally fine and isn’t harmful? The Russians still use asbestos and say it’s a plot by the west that we got rid of asbestos in our buildings. (Don’t shoot the messenger here, I have no dog in this fight and am not expressing an opinion)
Asbestos is totally safe as long as it’s not friable and you don’t sand it or disturb the fibers. Mesothelioma was a major problem if you were repeatedly exposed to asbestos. It’s present in nature and especially in soil in small concentrations. What makes it dangerous is if you’re constantly breathing it in. You would be doing that if you ran a buffer over asbestos tile for years, or if you worked in a space with asbestos pipe insulation, or if your job was to install asbestos siding or sheet flooring or formica(many adhesives contained it). Even gypsum wallboard contained asbestos up through the 80’s. It’s precisely its ubiquity as a building material that makes it dangerous because people are constantly disturbing it occupationally.
The problem is that not disturbing the fibers is impossible if you work with it at all, and workers in Russia still suffer from life-changing injuries. Disposing of it safely is also not realistically possible. The regulator just doesn't care, it's as simple as that. Of course they don't "think it's safe" as GP said, there's a ton of research and practice on the opposite and they set a specific (pretty low) limit on the exposure. But they turn a blind eye to the fact it's impossible to enforce and will never be followed in practice as long as asbestos is still being used anywhere. This is why asbestos use is banned everywhere, and this is the issue with Russian regulations, they give a tiny bit of economy a priority over public health, using the convenient research that pretty much "натягивает сову на глобус" in trying to downplay the hazard, if you actually read the relevant studies in Russian.
You are expressing disinformation. The actual regulations are very different from what you make it seem.
Why is it that right now there is still on the frontpage of an "article being found flawed after 6k citations " ( https://statmodeling.stat.columbia.edu/2026/01/22/aking/ ) but this random article coming out of nowhere makes the front page on the same day?
People really should get it and stop sharing newly published papers to the general public. The value of one single academic paper is exactly 0. Even a handful of such articles still has 0 value to the general public. This is only of interest to other academics (or labs, countries, etc.) who may have the power to reproduce it in a controlled environment.
Be very skeptical of correlations like this that have dubious or poorly understood causation. Be even more skeptical if they are about day-to-day stuff that would likely have large swaths of people able to reproduce something like it on huge scales yet they haven't. Extraordinary claims require extraordinary evidence.
You can also look at all the papers it's citing too...
This article is not making an extraordinary claim, and your offence is hyperbolic. Analysis of research should not be restricted to the academe, but careful not to cherry puck research.
It seems like a pretty extraordinary claim to me.
Considering the percentage of live mitochondria that are exposed to external light in a human this seems like an enormous effect. The effect we'd expect from publication bias though is already pretty big. I'm going to go with the latter until we've got some replication, and a plausible mechanism (like.. why wouldn't whales be badly sick if this was a thing?).
I don't know about the mitochondria bit, but it is plausible that work performance is affected by light spectrum. The n=22 is too small, but replication or larger studies is an obvious next step. Let's hope the researchers in this field use pre registration.
The article mentions that unlike visible light, which is mostly absorbed by the skin, near infrared light penetrates deep into the body and the lowest frequencies of the Solar spectrum pass through the entire body.
This explains why most mitochondria are exposed to infrared light, even those deep in the body.
The article also mentions an inhibiting effect of blue and violet light upon mitochondria. For that it should be valid what you say, that this effect can happen only in the superficial layer of the body, because both skin and blood strongly absorb such light.
Even if that is true, we humans tend to have clothes on, and keep indoors. Considering that the sun is WAY brighter (several orders of magnitude) than fluorescent bulbs are, this still sounds implausible, if you compare it to just going outside for a while.