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?"

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?

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.

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.

> 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.

> 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.

"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

> 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.

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".

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).

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.

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.)

Yes, OP incorrectly quoted voltage rather than frequency.

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.

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.

It's a poorly controlled experiment.

https://news.ycombinator.com/item?id=46764382

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.

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?

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’.

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

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).

Incandescent, by miles. Not even in the same ballpark. Even just candlelight beats led.

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.

How is "full spectrum" defined in this case? Visible spectrum is not the subject of the paper, as they care about infrared.

Call me when there's lights with a cri r9 of 99

>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

Are we also going to ban powerful computers since they use lots of power?

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.

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

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.

There's a mostly-unsubstantiated-by-data belief that LED lighting can cause health problems by some combination of flickering and narrow color spectrum.

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)

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?).