> Many LED systems use a dimming technique that rapidly switches the light on and off (sometimes hundreds of times per second). While this is invisible as flicker to the naked eye under normal conditions, eye movements can expose it
This is what I've always felt too, but if you talk to any lighting "expert", they'll say "no that's simply not the case with LED lighting since the year... 2009 or whatever ...". Highly suspect.
I find it easy to detect. If I wave my hand in front of my face quickly, the movement looks choppy instead of being just a blur. I can often tell lighting is cheep LED even without doing this. Movement just feels off. It is mildly annoying, but I can mostly ignore it.
> This is what I've always felt too, but if you talk to any lighting "expert", they'll say "no that's simply not the case with LED lighting since the year... 2009 or whatever ...". Highly suspect.
Way before the Internet I had games running at 50 Hz (PAL). And we fully knew the difference between, say, a 2D game scrolling at full-frame rate and a game running a 25 fps: we could tell immediately. Same for intros and demos.
Yet the number of times I had armchair experts explain me, despite me literally seeing with my own eyes the difference, that "the human eye cannot discern more than 24 fps". Teachers. Friends of my parents. My parents.
Later on I could tell a CRT running Windows @ 60 Hz vs 75 Hz in a split second: I simply could tell.
And still: same armchair experts "you cannot detect that, your eyes cannot physically detect more than 24 fps, because science!".
It's the absolute worst thing: you see something with your own eyes, other people see it with their own eyes. And yet "experts" explain to you "that is impossible".
While you could fucking literally demo it to them: but they're not interested "becuz it's impossssssible".
I hate LED lighting. Or at least I hate having only LED lighting. But there's IMO a simple trick to make the lighting much warmer and reduce the flicker (even if you don't consciously detect it, like 60 fps vs 75 fps: it's simply there) and still keep electricity consumption in check: just have one incandescent light bulb per room. Maybe two in the living room.
This immediately gives the feeling of a much warmer place (and, technically speaking, it is actually... warmer, ah!).
You can still legally, even in the EU, buy "special purpose", incandescent lamps that give a very nice warm yellowish light.
Just don't forget to wait if you plan to touch one after turning it off because they really get very warm.
Now of course you do that and you'll have sore people say: "even one incandescent lamp is too much, you should be 100% LED, not 95% LED, to save the planet!" followed by "we should ask the EU (and others) to ban once and for all ALL incandescent lightbulbs".
Basically: go order on Amazon or whatever a few small "special purpose" incandescent light and some little lamp to put them in. Put one in each room.
> ...there's IMO a simple trick to make the lighting much warmer...
Gross. That orange light is nasty. Light that's the color of the noontime sun during a clear day is far superior. People say "Oh, it looks so sterile and clinical!". I say "Jeeze... just give it a week or two. You'll wonder how you ever dealt with having every white thing look like UV-damaged formerly-white plastic.".
I do agree that headache/disorientation-inducing flicker is awful, but disagree that setting up an incandescent bulb would do all that much for it. Better to replace the garbage LED blinkers with something that's not broken.
There's color temperature: warm white (~2800K), neutral white (~4000K), or cool white (~5000K and up). This is a matter of personal taste and what you're used to. Perception/preference may vary depending on lighting level: one may prefer ~4500K in a bright room, but prefer warm(er) white if same room is dimly lit.
Then there's the quality of the spectrum a LED outputs, usually denoted by color rendering index (CRI). 70 or lower is poor (cheap), 80+ is good enough for most uses, 90+ is high quality. Pro photographers may seek out specialty 95CRI LED lighting, or go for halogen lamps.
Parents' problem has nothing to do with the above! Flicker is caused by non-constant current put through the LED(s). Usually caused by cheap/crappy driver electronics integrated in a LED bulb.
There's ways around this. So you can have LED lighting that's nice to look at, flicker-free & efficient. No need to bring in incandescents. But it takes effort to find a fixture with a high-CRI powerLED of your chosen color, and combine that with driver electronics which puts a constant current through the LED (as opposed to varying current whose average is constant).
Phillips “Ultra Definition” LEDs have less flicker than incandescent bulbs, so might work without needed to add an incandescent to the room. Here’s a review of several LEDs with measurements of various things including flicker.
Well, I was one of those "armchair" specialists until I got a system why could sustain 60 FPS and I couldn't deny there was a difference between 30 FPS and 60 FPS, even though on the paper 25 FPS "should be enough for everyone".
(from TFA:)
> During a rapid eye movement, the flickering light source can paint a streak of ghost images across the retina
So REM could explain it? Maybe it is somehow variable among people?
As I understand it, 24fps was the point at which a convincing illusion of continuous-motion could be achieved with a traditional movie-theater projector.
It is not the maximum perceptible frame rate. In fact, I think that perceptible-frame-rate varies across the eye and is faster in peripheral vision.
> ... they'll say "no that's simply not the case with LED lighting since the year... 2009 or whatever ..."
Yeah. Making things even worse is the fact that wear and tear from these things aging can make them really terrible to be in the same room with... but this doesn't seem to be something that folks are generally aware of, and is almost certainly something that approximately no one tests for.
I used to have rock-solid dimmable Cree LED bulbs in my fixtures. When I installed them, they were great. I had them installed for something like five years. I blamed the headaches I had been regularly getting over the previous ~six months on poor diet, exercise... the usual things. After noticing that nights spent with the lights off correlated with reduced or absent headaches, I replaced the bulbs with another highly-regarded brand and model. Other than the occasional caffeine-withdrawl headache, I haven't had a headache since.
I don't know if every LED bulb -er- "wears bad" like this, but I'd be surprised to hear that most of them do not. "The thing still makes light, but gives a notable subset of the population godawful headaches." doesn't seem to be the sort of thing that politicians who are "concerned" about the environment will care much about. That fact would really complicate the "They last for ten+ years, which massively reduces waste!" narrative.
This is what I've always felt too, but if you talk to any lighting "expert", they'll say "no that's simply not the case with LED lighting since the year... 2009 or whatever ...". Highly suspect.