This is one of those topics that I researched a lot when I bought a new home recently. While LED lights seem awesome at the first sight (low power consumption! No warmup time!) when you dig a little deeper you'll find that most LEDs are far from perfect:
1. Lots of LEDs flicker. Shitty ones with twice the frequency of the main current (so 100/120 Hz) While you might not notice this it causes eye strain and can lead to eye fatigue, headaches, migraines.
2. Most LEDs have a low CRI (Color Rendering Index, or called Ra which is one standard to measure it), this means that they do not emit light in certain frequencies causing objects to look dull/gray. Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% of a spectrum that covers most of the visible light.
If you look around you'll be able to find reasonably priced LEDs with 90+ Ra and no flicker, but its a pain in the ass to research it. Especially if you need something more special like a LED light strip for your kitchen.
No, the diodes don't, the drivers do. You are speaking to a technical audience ;)
> means that they do not emit light in certain frequencies causing objects to look dull/gray. Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% ...
Hardly. It means that they reproduce a set of 8 or 16 fixed frequencies from the ral pallete. It doesn't cover anything inbetween so it's just a rough rule of thumb. It doesn't cover colors in the far red (or was that violette on the other end of the soecteum?) at all.
Overall, overexposure of some frequencies, arguably to appear brighter and fuller, has damaged musuem pieces--Radiation stress, really. All they can do now is individual tests with photometric instruments, because they can't trust CRI. Same for horticultural lighting, which hasn't really taken of anyway.
Edit: Some manufacturers publish reference curves in the datasheets for their emitters, however I don't know how accurate these are under varying conditions and across batches.
> 1. Lots of LEDs flicker. Shitty ones with twice the frequency of the main current (so 100/120 Hz) While you might not notice this it causes eye strain and can lead to eye fatigue, headaches, migraines.
That's with a full rectifier. It's even cheaper to go half-rectifier and end up with 50/60Hz flicker. Being cheaper, this happens a lot.
I'm super sensitive to this flickering and will get nausea after sitting in some cheap LED lighting while other people hardly seem to notice.
I jokingly say that with cheap 50Hz LED lighting and 60fps screens, virtual reality now has a higher frame rate than real reality.
> If you look around you'll be able to find reasonably priced LEDs with 90+ Ra and no flicker, but its a pain in the ass to research it
For people in North America, I'd recommend https://www.hyperikon.com/ for LED products from screw-in bulbs to large area lights with high CRI and no flicker (note: a few products don't have high CRI, so do check the product page). They offer a good range of color temperatures too.
> Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% of a spectrum that covers most of the visible light.
That's not what Ra means. It's not a percentage - in fact, something with a perfectly flat distribution covering all the visible spectrum would not have especially high CRI, because that's significantly different from the spectrum of blackbody radiation, on which CRI is based. The actual algorithm for calculating CRI doesn't fit nicely in a comment, but it's in the Wikipedia page: https://en.wikipedia.org/wiki/Color_rendering_index
Edit: missed the negation - CRI is not high for a perfectly flat spectrum.
Note that CRI (Colour Rendering Index) is a bit bogus. It came about when florescent lights became a thing and was originally based on a sheet of printed colour swatches. RGB LED lighting promoters have pointed out that CRI doesn't really reflect the goodness of light sources other than florescent in practice.
Mine are all Brightgreen [1] high-CRI warm white downlights and they’re pretty great. They’re pretty pricy compared to the cheap no-name brands though (going for the “designer”/premium market I suppose).
'Is It Snappy?' is an iOS app that I use to diagnose whether LED bulbs are going to be shit in stores before I buy them. The IKEA bulbs have been cheap and decent.
I hate lighting that flickers and will often notice it when other people do not. A few friends also notice flickering that most people don't detect. It takes tens of kHz before I won't notice a stop-motion effect like a strobe light with moving objects.
LEDs do not have to flicker, but supplying low-ripple, constant-current DC power is not as cheap as ways of powering LEDs that do result in flicker.
Last year, I was contemplating bootstrapping a startup that sold full-spectrum LEDs with a controllable blue element for home and office use. Think Flux but for real lights.
I got so far as inspecting factories in Shenzhen, finding a partner supplier, and building some prototypes with my existing manufacturing contacts.
Ultimately, I ran out of time (launched another product instead) - but it always bugged me that I wasn't able to bring this product to market.
If anyone would be interested in picking up where I left off - I'd be interested in partnering.
In The Netherlands some cyclists have this brilliant idea to put their lights on flash/flicker. I suppose some think they'll be easier to get noticed.
It is not allowed by law (the light has to be either constantly on, or it may be turned off if it isn't dark), it can trigger epilepsy, it is distracting, and it is selfish and not 'cool' at all.
It also appears to be common in PC desktops to enable all kind of LEDs, without allowing them to be disabled. Especially in all kind of colours (which Razor dubbed 'Chroma'). Not my cup of tea, a waste of aesthetic and electricity but the worst thing about it is that I pay premium for such feature because it is deemed 'cool' by the target market.
FWIW, I use a strong light in the morning to wake up. It doesn't flash.
Well, I don't like those lights either, but calling it selfish, is kinda hard when you compare it to how many cyclists get killed every year because some motorist didn't see them.
There are quite a lot of these in the UK too, again I'm not sure of the legality.
As a driver I've two things to say about them.
Firstly, they do make it easier to spot the cyclist over a solid light so that's a good thing. However, it's almost impossible to track their movement and that is a very very bad thing.
The best solution I feel is to have a flashing light which draws attention in addition to a solid light which is much easier to keep track of in your peripheral.
Blinking lights save power and lead to longer battery life, hence the cycle lights with different blink settings. The power savings can be substantial, one of the back lights I use switches between 'full on' (3 leds, full power) and 'walking blink' (¼ second on/off). Subtract the (negligible) power used by the timer IC and you end up with a factor 6 difference in favour of the blinking light. Here in Sweden blinking lights are still allowed, one of the places where you'll meet them is on the railroad as Swedish trains have blinking back lights.
Flashing bike lights are ubiquitous in the United States. I prefer them because I can distinguish a cyclist from what could be a slow car missing a tail light.
Here in the south of Spain I regularly see scooters (mopeds) that are 20+ years old. Older scooters often have headlights that are so dim you can barely see them (the bulbs just get dimmer, they don't burn out). As a car driver I'd much prefer to see a bright and flashing light so I notice the vehicle, and a bicycle doesn't make any noise so I'm not going to hear it.
If you find blinking lights on cyclists annoying, that means you noticed them. So they accomplish their mission. Blinking lights are significantly easier to notice from peripheral vision.
This should be flagged, tagged, or somehow made to be seen by new vistors to the site, as I had to track this down to figure out what this site was even on about.
I was impressed by how fast and uncluttered this site is. In case someone else is wondering: It seems to be running https://flarum.org/, a PHP forum with a Mithril JS front-end
But it's terrible for search, both internal and external(Google).
Why ?
Let's start with internal search. Ctrl-f fails in thread search. No other mechanism to search inside a thread.
And about external search:
Permalinks to individual comments - great for the search engine when you request a very specific thing - a specific niche comment from this site could get ranked highly in google.
Also, it's making it easy to link to a great comment is import. Impossible here.
Permalinks to webpages that contain full threads - lots of relevant text for the search engine to chew on. But in flarum the content lazily loads. So maybe Google wouldn't be able to chew on all the comments.
And the fact that when Google finds a thread from the site, he doesn't say how many comments per thread , indicates that he doesn't see this as a forum, which could be bad
And all this is a real shame - it's a community with really valuable content.
Perhaps it's the subject matter that has driven the site design towards a paler pastel colour palette, but I find it quite pleasing to the eye.
Although I do wonder about accessibility. Some of the lighter colours don't pass WCAG recommendations for contrast. But it's rare to find a website outside of gov.uk that even comes close.
Let me shed some light on how you can drive LEDs from an AC power source. Naturally the worst techniques are usually the cheapest. To add to the complexity, directives like EnergyStar are aiming for power factor >0.9 in lighting above 3W. Maintaining high power factor (sin^2 input power) while having low lighting ripple (constant output power) requires some method of of storing energy. In methods 1,2,3 (and 4 depending), neither high power factor nor good lighting ripple is achieved, but very low cost is.
Note that this info is for fairly low power LEDs. When you start having high power LEDs, regulations may require better power electronics, and the cost of the electronics might be amortized against the cost of the thermal cooling solution, etc, so you can make a more expensive electronics package.
1) By stringing ~ 180v of LEDs in series, and adding a current limiting resistor, you can drive the whole thing from the AC line. This has terrible variability (short light spikes every 60hz, and the thermal effects will change the LED properties so much that you could easily have 2x light intensity change as they warm up) and poor total illumination (as most of the cycle is spent with the AC waveform lower than the needed voltage. I haven't seen this in the wild, as option 2 isn't much more expensive and far better.
2) Use a single diode + capacitor rectifier to generate ~180v, and then have a similar string as in (1). This gives far better illumination (the capacitor will probably stay in the 160-180v range), but still has substantial 50/60hz ripple based on the size of the capacitor
3) Similar to (2) but use a full bridge rectifier instead of a single diode. As we are now driven by a rectified sine wave, the ripple voltage will ~half, and the ripple frequency will now be 100/120hz.
4) Many applications don't have ~60 LEDs in series, so you can't drive directly from the rectified AC line. The first stage is a rectifier, and a second stage most likely is a buck converter. The quality of the light out of this depends on how much you care about power factor. Chips like NCL30288, for example, maintain high power factor and fairly low lighting ripple. Most people won't notice this.
5) Particularly in higher power lighting, a separate power factor correcting stage achieves high power factor, and a second stage generates a constant current that should have exceptionally low luminous intensity ripple (if designed right). The ripple frequency should be in the hundreds of kHz as well, so I don't think any eye could notice this.
And don't get started on dimming, I haven't found a product on the market that does non-phase cut dimming in <20W lights.
One interesting use for flickering LEDs is to help figure out the readout speed and clock rate of a digital camera sensor by exploiting the rolling shutter. Some discussion and experiments on this technique can be found here: https://www.magiclantern.fm/forum/index.php?topic=23040.0
Tis the season for PWM-induced headaches from cheap LED Christmas lights.
I'm curious if folks in countries with 50Hz mains have the same issue. At that point it might be so bad that products without at least a full bridge rectifier would be unsellable.
Interesting. Reading some of the comments they really run the gamut (no pun intended). It's reassuring to see though that people are starting to pay attention to this. For myself, it is the flicker (PWM) of some LED drivers that I am uncomfortable with. I went through a few different brands of LED track lights before finding one where I could perceive no flicker.
Similarly for LED lightning in the garage.
For the kitchen I had a need for rope lighting and never did find LED/driver combo that I was happy with.
Here's a trick that I've found useful: If you have a phone that can do slow motion capture (I have a Pixel 2, but this also works with an iPhone), go to a Home Depot or Lowe's and take a slo-mo (240fps) video of the LED bulbs they have on display. Most flicker horribly on playback, including the expensive Cree bulbs.
The built-in LED spotlights that came with my house flicker like a rave concert whenever I capture a video in slo-mo. It's unsettling.
Phillips LEDs, especially the Scene Switch bulbs, are flicker-free according to my tests. Surprisingly, older CFL bulbs flicker much less than LEDs.
Well, if its a light in your house, it is within your control. What if it is at work? In the public transport? On the street? In a grocery store? At a customer? If you suffer from LED strain, it'll hamper your ability to function in society. All this reminds me a bit of Chuck in Better Call Saul (portrayed by Michael McKean). Regardless of what he exactly had, the man was ill.
This is interesting. If LED lights pulse so quickly that we don't notice the flashing, how are these people able to perceive it in a way that causes them pain?
I Learned that if low freq LED flicker strains your eyes, then there's a chance you'll feel discomfort from emerging display HDR color dithering as well. For example, if the panel is 8bit but it shows you 10bit color space by 8 bit plus A-FRC.
Bought a 2018 Macbook pro and it produces similar symptoms like years ago when I had a laptop with bad low freq LED backlight.
Right now using a late 2010 and a 2013 Macbook Pro both with native screens and on external screens and it does not make my head hurt. 2018 one strains me both on native screen and on my otherwise good daily driver BenQ monitor.
Related Question: Is it possible for AM-OLED to be PWM free? ( Apart from setting it at maximum brightness ). Or would we have to stick to this until MicroLED comes.... which is still years away.
Edit: I know W-OLED used by LG does not have PWM problem, but that is not for mobile uses.
In summary they are saying that low frequency (240Hz) PWM is used for amoled because it decreases sub-pixel wear, it prevents color distortion, it's cheaper. So it looks like this won't change. I got an amoled phone and was surprised that the experience was worse than LCD (for me - it seems to depend a lot on the individual). Didn't even know that PWM was used until I started googling eystrain and amoled. Anyway, I sent the phone back.
Check notebookcheck's reviews to find AMOLED phones that eiter don't use PWM (I think it's only about 2 of them) or only use it above a certain brightness level. For example, the Axon 7 Mini. It seems those displays started to show up at around 2016.
A small 60 Hz flicker will remain though, similar to as seen on OLED TVs.
I'm sensitive to this flickering as well. Cars in motion, traffic lights, destination/passenger information displays, POS, sometimes ATMs. Though the "car-thing" mostly faded away over the last few years. They seem to got that right now. Anyways, i tried some of them over the last decade and they were all trash, made bad light, needed time to warm up, had coil whine or buzzing and broke after a few months. Then in May this year i tried some again and they were absolutely OK. It's called "LED-Retrofit" which means it fits in old sockets, based on this technology:
https://en.wikipedia.org/wiki/LED_filament
No dimming, no "smarts", no color/ambilight etc. Just works as it should. Mine are from Osram, for something like 6 to 12 Euros a piece, directly plugged into E27/E14 sockets at 230V@50Hz. And most importantly no ugly interactions with my screens running at 60Hz. This reminds me of scissors, for a long time they needed to be resharpened. Then, since maybe two, or at least one decade ago you could get good and f......g dangerous scissors which cut through almost anything whitout getting blunt/dull for next to nothing.
Now seems to be the point in time where this happened for LED-lighting. At least when it's based on this "LED-Filament"-thing. HTH.
Sure, when the AC is on in late spring/summer, LED makes a heck of a lot more sense. But when the heat is on, filament lightbulbs serve as space heaters as well as glowy-warm lights.
And with the whole open question of blue light and retinopathy, tells me that until this is resolved that again, incandescents are better than LEDs. I already knew that those damned 'blue LEDs' are painful at night. I now know why.
As someone who suffers from this since the arrival of LED backlighting, I wonder if there are lighting technologies on their way that will eliminate the issue?
[+] [-] sydd|7 years ago|reply
1. Lots of LEDs flicker. Shitty ones with twice the frequency of the main current (so 100/120 Hz) While you might not notice this it causes eye strain and can lead to eye fatigue, headaches, migraines.
2. Most LEDs have a low CRI (Color Rendering Index, or called Ra which is one standard to measure it), this means that they do not emit light in certain frequencies causing objects to look dull/gray. Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% of a spectrum that covers most of the visible light.
If you look around you'll be able to find reasonably priced LEDs with 90+ Ra and no flicker, but its a pain in the ass to research it. Especially if you need something more special like a LED light strip for your kitchen.
[+] [-] posterboy|7 years ago|reply
No, the diodes don't, the drivers do. You are speaking to a technical audience ;)
> means that they do not emit light in certain frequencies causing objects to look dull/gray. Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% ...
Hardly. It means that they reproduce a set of 8 or 16 fixed frequencies from the ral pallete. It doesn't cover anything inbetween so it's just a rough rule of thumb. It doesn't cover colors in the far red (or was that violette on the other end of the soecteum?) at all.
Overall, overexposure of some frequencies, arguably to appear brighter and fuller, has damaged musuem pieces--Radiation stress, really. All they can do now is individual tests with photometric instruments, because they can't trust CRI. Same for horticultural lighting, which hasn't really taken of anyway.
Edit: Some manufacturers publish reference curves in the datasheets for their emitters, however I don't know how accurate these are under varying conditions and across batches.
[+] [-] remcob|7 years ago|reply
That's with a full rectifier. It's even cheaper to go half-rectifier and end up with 50/60Hz flicker. Being cheaper, this happens a lot.
I'm super sensitive to this flickering and will get nausea after sitting in some cheap LED lighting while other people hardly seem to notice.
I jokingly say that with cheap 50Hz LED lighting and 60fps screens, virtual reality now has a higher frame rate than real reality.
[+] [-] Zak|7 years ago|reply
For people in North America, I'd recommend https://www.hyperikon.com/ for LED products from screw-in bulbs to large area lights with high CRI and no flicker (note: a few products don't have high CRI, so do check the product page). They offer a good range of color temperatures too.
> Most LED lamps have a Ra value of 80, meaning that they emit on average in the 80% of a spectrum that covers most of the visible light.
That's not what Ra means. It's not a percentage - in fact, something with a perfectly flat distribution covering all the visible spectrum would not have especially high CRI, because that's significantly different from the spectrum of blackbody radiation, on which CRI is based. The actual algorithm for calculating CRI doesn't fit nicely in a comment, but it's in the Wikipedia page: https://en.wikipedia.org/wiki/Color_rendering_index
Edit: missed the negation - CRI is not high for a perfectly flat spectrum.
[+] [-] upofadown|7 years ago|reply
[+] [-] oxplot|7 years ago|reply
[1]: https://www.yujiintl.com
[+] [-] jacobush|7 years ago|reply
[+] [-] Tepix|7 years ago|reply
[+] [-] stephen_g|7 years ago|reply
1. https://brightgreen.com
[+] [-] joecool1029|7 years ago|reply
Old HN thread about the iOS app: https://news.ycombinator.com/item?id=14023196
[+] [-] Zak|7 years ago|reply
LEDs do not have to flicker, but supplying low-ripple, constant-current DC power is not as cheap as ways of powering LEDs that do result in flicker.
[+] [-] kweks|7 years ago|reply
I got so far as inspecting factories in Shenzhen, finding a partner supplier, and building some prototypes with my existing manufacturing contacts.
Ultimately, I ran out of time (launched another product instead) - but it always bugged me that I wasn't able to bring this product to market.
If anyone would be interested in picking up where I left off - I'd be interested in partnering.
Shoot an email to public @ proxmark dot com
[+] [-] Fnoord|7 years ago|reply
It is not allowed by law (the light has to be either constantly on, or it may be turned off if it isn't dark), it can trigger epilepsy, it is distracting, and it is selfish and not 'cool' at all.
It also appears to be common in PC desktops to enable all kind of LEDs, without allowing them to be disabled. Especially in all kind of colours (which Razor dubbed 'Chroma'). Not my cup of tea, a waste of aesthetic and electricity but the worst thing about it is that I pay premium for such feature because it is deemed 'cool' by the target market.
FWIW, I use a strong light in the morning to wake up. It doesn't flash.
[+] [-] arendtio|7 years ago|reply
[+] [-] Steve44|7 years ago|reply
As a driver I've two things to say about them.
Firstly, they do make it easier to spot the cyclist over a solid light so that's a good thing. However, it's almost impossible to track their movement and that is a very very bad thing.
The best solution I feel is to have a flashing light which draws attention in addition to a solid light which is much easier to keep track of in your peripheral.
[+] [-] Yetanfou|7 years ago|reply
[+] [-] fingerlocks|7 years ago|reply
[+] [-] Tharkun|7 years ago|reply
[+] [-] fyfy18|7 years ago|reply
[+] [-] monkeynotes|7 years ago|reply
[+] [-] PedroBatista|7 years ago|reply
But cyclists tend to get a pass with almost everything for some reason.
[+] [-] akvadrako|7 years ago|reply
And as they are illegal to use they should probably be illegal to buy, at least when marketed as bike lamps.
[+] [-] cimmanom|7 years ago|reply
[+] [-] adrianN|7 years ago|reply
[+] [-] jeremy7600|7 years ago|reply
https://ledstrain.org/d/19-welcome-to-led-strain
[+] [-] lorenzk|7 years ago|reply
[+] [-] jeremy7600|7 years ago|reply
Horrible UX. Whats the point of the site? What is LED Strain? where am I supposed to figure that out?
[+] [-] dbg31415|7 years ago|reply
If I were going to build a forum today using an open-source platform, I'd probably go with Discourse.
* Discourse - Civilized Discussion || https://www.discourse.org/
[+] [-] petra|7 years ago|reply
But it's terrible for search, both internal and external(Google).
Why ?
Let's start with internal search. Ctrl-f fails in thread search. No other mechanism to search inside a thread.
And about external search:
Permalinks to individual comments - great for the search engine when you request a very specific thing - a specific niche comment from this site could get ranked highly in google.
Also, it's making it easy to link to a great comment is import. Impossible here.
Permalinks to webpages that contain full threads - lots of relevant text for the search engine to chew on. But in flarum the content lazily loads. So maybe Google wouldn't be able to chew on all the comments.
And the fact that when Google finds a thread from the site, he doesn't say how many comments per thread , indicates that he doesn't see this as a forum, which could be bad
And all this is a real shame - it's a community with really valuable content.
[+] [-] jspash|7 years ago|reply
Although I do wonder about accessibility. Some of the lighter colours don't pass WCAG recommendations for contrast. But it's rare to find a website outside of gov.uk that even comes close.
[+] [-] sephamorr|7 years ago|reply
Note that this info is for fairly low power LEDs. When you start having high power LEDs, regulations may require better power electronics, and the cost of the electronics might be amortized against the cost of the thermal cooling solution, etc, so you can make a more expensive electronics package.
1) By stringing ~ 180v of LEDs in series, and adding a current limiting resistor, you can drive the whole thing from the AC line. This has terrible variability (short light spikes every 60hz, and the thermal effects will change the LED properties so much that you could easily have 2x light intensity change as they warm up) and poor total illumination (as most of the cycle is spent with the AC waveform lower than the needed voltage. I haven't seen this in the wild, as option 2 isn't much more expensive and far better.
2) Use a single diode + capacitor rectifier to generate ~180v, and then have a similar string as in (1). This gives far better illumination (the capacitor will probably stay in the 160-180v range), but still has substantial 50/60hz ripple based on the size of the capacitor
3) Similar to (2) but use a full bridge rectifier instead of a single diode. As we are now driven by a rectified sine wave, the ripple voltage will ~half, and the ripple frequency will now be 100/120hz.
4) Many applications don't have ~60 LEDs in series, so you can't drive directly from the rectified AC line. The first stage is a rectifier, and a second stage most likely is a buck converter. The quality of the light out of this depends on how much you care about power factor. Chips like NCL30288, for example, maintain high power factor and fairly low lighting ripple. Most people won't notice this.
5) Particularly in higher power lighting, a separate power factor correcting stage achieves high power factor, and a second stage generates a constant current that should have exceptionally low luminous intensity ripple (if designed right). The ripple frequency should be in the hundreds of kHz as well, so I don't think any eye could notice this.
And don't get started on dimming, I haven't found a product on the market that does non-phase cut dimming in <20W lights.
[+] [-] chris_overseas|7 years ago|reply
[+] [-] jcims|7 years ago|reply
I'm curious if folks in countries with 50Hz mains have the same issue. At that point it might be so bad that products without at least a full bridge rectifier would be unsellable.
[+] [-] JKCalhoun|7 years ago|reply
Similarly for LED lightning in the garage.
For the kitchen I had a need for rope lighting and never did find LED/driver combo that I was happy with.
[+] [-] copperx|7 years ago|reply
The built-in LED spotlights that came with my house flicker like a rave concert whenever I capture a video in slo-mo. It's unsettling.
Phillips LEDs, especially the Scene Switch bulbs, are flicker-free according to my tests. Surprisingly, older CFL bulbs flicker much less than LEDs.
[+] [-] Fnoord|7 years ago|reply
[+] [-] fenwick67|7 years ago|reply
Clicking your teeth together makes it pretty apparent usually, the segments will appear to jump around. Try it at home!
[+] [-] fermentation|7 years ago|reply
[+] [-] 2700K|7 years ago|reply
Bought a 2018 Macbook pro and it produces similar symptoms like years ago when I had a laptop with bad low freq LED backlight.
Right now using a late 2010 and a 2013 Macbook Pro both with native screens and on external screens and it does not make my head hurt. 2018 one strains me both on native screen and on my otherwise good daily driver BenQ monitor.
[+] [-] ksec|7 years ago|reply
Edit: I know W-OLED used by LG does not have PWM problem, but that is not for mobile uses.
[+] [-] discreteevent|7 years ago|reply
https://www.reddit.com/r/apple/comments/7uv6m3/iphone_x_uses...
In summary they are saying that low frequency (240Hz) PWM is used for amoled because it decreases sub-pixel wear, it prevents color distortion, it's cheaper. So it looks like this won't change. I got an amoled phone and was surprised that the experience was worse than LCD (for me - it seems to depend a lot on the individual). Didn't even know that PWM was used until I started googling eystrain and amoled. Anyway, I sent the phone back.
[+] [-] kmeier|7 years ago|reply
[+] [-] LargoLasskhyfv|7 years ago|reply
(edit spelling)
[+] [-] baybal2|7 years ago|reply
[+] [-] jeremy7600|7 years ago|reply
https://ledstrain.org/d/19-welcome-to-led-strain
[+] [-] jeremy7600|7 years ago|reply
[+] [-] crankylinuxuser|7 years ago|reply
Sure, when the AC is on in late spring/summer, LED makes a heck of a lot more sense. But when the heat is on, filament lightbulbs serve as space heaters as well as glowy-warm lights.
And with the whole open question of blue light and retinopathy, tells me that until this is resolved that again, incandescents are better than LEDs. I already knew that those damned 'blue LEDs' are painful at night. I now know why.
[+] [-] vostok|7 years ago|reply
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] 33degrees|7 years ago|reply