[HN Gopher] LED lighting undermines visual performance unless su...
___________________________________________________________________
LED lighting undermines visual performance unless supplemented by
wider spectra
Author : bookofjoe
Score : 196 points
Date : 2026-01-25 21:44 UTC (1 days ago)
(HTM) web link (www.nature.com)
(TXT) w3m dump (www.nature.com)
| userbinator wrote:
| 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.
| rpcope1 wrote:
| 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.
| VagabundoP wrote:
| Even a colour filter would help with the harshness.
| adrian_b wrote:
| 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.
| yial wrote:
| 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.
| adrian_b wrote:
| 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.
| skandinaff wrote:
| 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.
| orbital-decay wrote:
| They're saying that the visual performance is indirectly
| affected by invisible wavelengths somehow. Not that you can see
| the difference between two types.
| siffin wrote:
| 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.
| orbital-decay wrote:
| _> 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.
| AlanYx wrote:
| 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.
| nicoburns wrote:
| 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.
| kuschku wrote:
| 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.
| nicoburns wrote:
| 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.
| kuschku wrote:
| 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.
| scythe wrote:
| 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.
| zahirbmirza wrote:
| wow - had no idea these things existed, fascinating.
| RivieraKid wrote:
| The CRI is an imperfect metric, I watch for both CRI and R9,
| both should be high.
| Saris wrote:
| 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.
| mjmas wrote:
| Someone please tell the Australian government now that we've
| essentially banned other forms of lighting. (except fluorescent)
| novok wrote:
| 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.
| krackers wrote:
| >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
| novok wrote:
| 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.
| krackers wrote:
| 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.
| u1hcw9nx wrote:
| You can buy full spectrum LED lights (99 CRI, or grow lamps)
|
| The article uses LED as synonym for typical LED lightning.
| ale42 wrote:
| How is "full spectrum" defined in this case? Visible spectrum
| is not the subject of the paper, as they care about infrared.
| krackers wrote:
| 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.
| KennyBlanken wrote:
| 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.
| krackers wrote:
| 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).
| ChadNauseam wrote:
| 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.)
| TeMPOraL wrote:
| 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.
| ale42 wrote:
| 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.
| krackers wrote:
| 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
| navigate8310 wrote:
| Have you tried LEDVance?
| ale42 wrote:
| > 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.
| u1hcw9nx wrote:
| Specialized stores or online. If enough people start
| buying them, they become popular and cheaper.
| nicoburns wrote:
| 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.
| RobotToaster wrote:
| Call me when there's lights with a cri r9 of 99
| dangus wrote:
| 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?
| mjmas wrote:
| Are we also going to ban powerful computers since they use
| lots of power?
| Scoundreller wrote:
| I hope they don't come for my 386 with 14" CRT
| yehat wrote:
| Sad to say, but concerning the PC, seems we're moving in
| that direction pretty fast.
| kuschku wrote:
| 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.)
| dangus wrote:
| 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.
| noosphr wrote:
| 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.
| rrr_oh_man wrote:
| > It's amazing how we're replaying the asbestos playbook a
| century later
|
| Can you elaborate?
| wincy wrote:
| 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)
| orbital-decay wrote:
| You are expressing disinformation. The actual regulations
| are very different from what you make it seem.
| throwaway173738 wrote:
| 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.
| orbital-decay wrote:
| 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
| "natiagivaet sovu na globus" in trying to downplay the
| hazard, if you actually read the relevant studies in
| Russian.
| sb057 wrote:
| There's a mostly-unsubstantiated-by-data belief that LED
| lighting can cause health problems by some combination of
| flickering and narrow color spectrum.
| NotGMan wrote:
| 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.
| AshamedCaptain wrote:
| Do you have evidence that this rock doesn't keep tigers
| away?
| noosphr wrote:
| I guess you know better than the scientist studying it: htt
| ps://www.sciencedirect.com/science/article/pii/S004896972..
| .
| tuyiown wrote:
| 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.
| Orygin wrote:
| 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).
| yehat wrote:
| 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?
| direwolf20 wrote:
| Maybe it causes eyestrain. It's unlikely to cause cancer.
| It reduces energy use, which reduces smog, which reduces
| cancer.
| Orygin wrote:
| 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?
| noosphr wrote:
| 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-...
| noosphr wrote:
| 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.
| Orygin wrote:
| > 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
| direwolf20 wrote:
| 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.
| noosphr wrote:
| 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
| cglouch wrote:
| where do you purchase yours out of curiosity? My incandescent
| light bulb dealer on Ebay stopped selling them...
| AshamedCaptain wrote:
| 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.
| novok wrote:
| You can also look at all the papers it's citing too...
| angry_octet wrote:
| 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.
| boxed wrote:
| 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?).
| angry_octet wrote:
| 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.
| adrian_b wrote:
| 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.
| boxed wrote:
| 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.
| HNisCIS wrote:
| 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.
| novok wrote:
| 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
| HNisCIS wrote:
| 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
| novok wrote:
| 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.
| HNisCIS wrote:
| Is "ask an AI" the new rtfm?
| hedora wrote:
| 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")
| sho_hn wrote:
| 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?
| wendy_kroy wrote:
| 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.
| elric wrote:
| 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?
| fragmede wrote:
| 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).
| marcosdumay wrote:
| 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.
| herf wrote:
| 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.
| londons_explore wrote:
| Indeed - these study results are fairly substantial _if_ they
| can be independently reproduced by more studies at bigger
| scales.
| bob1029 wrote:
| 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.
| PeterStuer wrote:
| 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.
| Cthulhu_ wrote:
| Which one of the two was better for it?
| PeterStuer wrote:
| Incandescent, by miles. Not even in the same ballpark. Even
| just candlelight beats led.
| adrian_b wrote:
| 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.
| imp0cat wrote:
| To put it bluntly, it could also be that your LED light
| sources are low-CRI junk.
| bayindirh wrote:
| 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.
| adrian_b wrote:
| 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.
| bayindirh wrote:
| 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", 25C/ 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.
| nicoburns wrote:
| 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.
| bayindirh wrote:
| 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.
| accidentallfact wrote:
| 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.
| guenthert wrote:
| 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
| accidentallfact wrote:
| >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.
| adrian_b wrote:
| 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.
| lgeorget wrote:
| 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?
| adrian_b wrote:
| 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.
| wtcactus wrote:
| 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.
| schiffern wrote:
| _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).
| zahirbmirza wrote:
| 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.
| oniony wrote:
| 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.
| lightedman wrote:
| 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.)
| zahirbmirza wrote:
| Yes! And this after image is distracting.
| mnw21cam wrote:
| 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.
| dv_dt wrote:
| 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?
| leoedin wrote:
| > 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.
| DeathArrow wrote:
| >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
| JKCalhoun wrote:
| "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-a
| mp.... and https://imgur.com/gallery/oh-darling-tube-
| amplifier-Lq2Sx
| johanvts wrote:
| 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.
| obidee2 wrote:
| 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.
| zahirbmirza wrote:
| 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
| johanvts wrote:
| Look for high Ra or CRI value. Dont buy cheap LED lights,
| they last for far too long.
| axus wrote:
| 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".
| nielsbot wrote:
| They do emit a lot of heat!
| abdullahkhalids wrote:
| 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.
| create-username wrote:
| 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
| Sharlin wrote:
| 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.
| SoftTalker wrote:
| 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.
| entropie wrote:
| 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
| frumper wrote:
| 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.
| mikeyouse wrote:
| 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.
| onestay42 wrote:
| I've seen some overheat themselves even in open air!
| graemep wrote:
| > 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.
| wongarsu wrote:
| 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
| fundatus wrote:
| > 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.
| palmotea wrote:
| > 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.
| wongarsu wrote:
| 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
| nerdponx wrote:
| 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.
| NwtnsMthd wrote:
| 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.
| graemep wrote:
| 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).
| Rebelgecko wrote:
| 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...
| dvdkon wrote:
| 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.
| fyrn_ wrote:
| Wouldn't the supply usually be either 50hz or 60hz depending in
| the country?
| kalium-xyz wrote:
| 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.
| DeathArrow wrote:
| 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
| DeathArrow wrote:
| 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.
| r_lee wrote:
| 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...
| zahirbmirza wrote:
| I miss the orange glow of sodium lamps that characterised cold
| dark and foggy english winter nights.
| r_lee wrote:
| 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
| nrjames wrote:
| 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?
| atopal wrote:
| 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.
| yarekt wrote:
| 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?
| johanvts wrote:
| Phillips, try searching for EyeComfort. I think all of
| their premium bulbs have 80+ Ra.
| graemep wrote:
| 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.
| atopal wrote:
| 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...
| johanvts wrote:
| 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.
| Paianni wrote:
| What's available depends on the form factor, but there are some
| manufacturers that offer some choice in the 2700k 90+cri space
| nowadays.
| SoftTalker wrote:
| 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.
| Saris wrote:
| 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.
| ck2 wrote:
| 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
| analog8374 wrote:
| Also, LED strobes to dim. Which is unpleasant.
| elric wrote:
| > 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?
| hnuser123456 wrote:
| 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.
| blacklion wrote:
| 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.
| mikkupikku wrote:
| 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.)
| buildbot wrote:
| 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.
| countWSS wrote:
| > (at least usually).
|
| Nope. Lots of people see the strobing. Its causes headaches if
| you focus on the lights.
| entropie wrote:
| 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.
| mikkupikku wrote:
| > _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.
| Onavo wrote:
| Why don't LED drivers just use plain continuous DC with no PWM?
| ternus wrote:
| 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.
| Saris wrote:
| Cost.
| rini17 wrote:
| 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).
| nerdponx wrote:
| 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.
| TheJoeMan wrote:
| 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.
| mikkupikku wrote:
| 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.
| daveloyall wrote:
| 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...
| pedrocr wrote:
| 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.
| mikeyouse wrote:
| 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.
| dwroberts wrote:
| 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
| roughly wrote:
| 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).
| nazgul17 wrote:
| 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) 1/4 the energy of an incandescent bulb.
|
| Or the minimum set of species yielding optimal outcomes,
| without the answer being "all of them"
| BizarroLand wrote:
| 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.
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