> You can't perceive that
I very easily can. I had to get rid of an otherwise good monitor a few years ago before I knew it used PWM to control the backlight (and before I even knew PWM was used at all for this functionality — I only had experience with CCFL backlight before that).
It was really annoying to look at, like looking directly at cheap fluorescent lighting. Miraculously, setting brightness to 100% fixed the issue.
By googling around, I found that it used PWM with a modulation frequency of 240 Hz, with a duty cycle of 100% at full brightness, which explained everything.
I can also easily perceive flickering of one of my flashlights, the only one that uses PWM at a frequency of a few hundred hertz. Other flashlights either run at multiple KHz, or don't use PWM at all, and either one is much easier on the eyes.
Some of us really do perceive this stuff, which can be hard to believe for some reason.
Next time you see a high refresh screen, move the cursor around rapidly. It's very easy to tell.
In gaming situations what they perceive may not be the actual "flicker" of frames but the input->to->display latency, which is a very different thing to notice.
The jumps from 30-40-60-72-144 are all pretty noticeable, but 144-240 is already very minimal and 240-360+ is pretty much quackery.
My partner and me both notice the difference between cheap LEDs and expensive ones (hue). Whe both cannot pinpoint it down.
You may not believe that people that can see 120->240Hz flicker exist, but we do. In this era of frequently-cheap-ass LED lighting, it's a goddamn curse.
It's really bad for me as I work in an LED and LASER facility. I handle ALL the PWM stuff while everyone else handles the simple led/resistor/connector board assemblies. EVERYTHING FLICKERS.
> EVERYTHING FLICKERS.
I absolutely could not handle that. My sincerest condolences.
I presume this is why you think that?
> ...between cheap LEDs and expensive ones (hue)...
If so, they're referring to the Hue brand of bulbs, rather than the color property. More evidence for the fact that they're talking about flicker is that they quoted this to indicate that they were replying to it:
> > Nah, LED lighting generally uses at least 200 Hz at a minimum. Some up to kHz. You can't perceive that.
Eh, they use what they can get away with. Nobody is out there policing flicker rates. Especially when you add a dimmer into the mix, there's a lot of room between good and bad, and when you're at the hardware store buying bulbs, there's not much to indicate which bulbs are terrible.
Lots of people don't seem to notice, so the terrible ones don't get returned often enough to get unstocked, and anyway, when you come back for more in 6 months, everything is different even if it has the same sku.
Not only flickering, but lots of other information about internationally available brands, including cheap Chinese stuff: CRI, real power use, etc.
Use your favorite online translator.
Actually, Energy Star and California's Title 24 have flicker standards. They may not go as far as some people like, but you can look for these certifications to know that a bulb at least meets a certain minimum standard.