LCD vs OLED, does it matter to you? Or do you not care either way?
LCD vs OLED, does it matter to you? Or do you not care either way?
You're viewing a single thread.
75 comments
-
Definitely! OLED is unusable for me because it has really bad PWM flickering. The majority of people can't see the screen flashing on and off like a strobe light, but many of us have eyes that do see the flashing, and it's awful.
I can't wait until a new display technology gets popular that doesn't use Pulse Width Modulation
-
Damn, so basically you can't use any high-end smartphones due to a biological reason outside your control? 😥 (because all high-end smartphones use OLED)
-
Yup. It really sucks. Being able to see things that are very quick is like a superpower, but as far as i can tell there's only downsides
-
-
I can see flicker in some 60 Hz LED lighting in the corner of my eyes, using the rods in the irises of my eye, when I can't see it using the cones in the pupil. Stick the light in the middle of my vision, and the flicker vanishes. Drove me nuts with some inexpensive, high-power corncob LED light bulbs that didn't have an electronic ballast, just fed wall power directly to an array of LEDs.
Wikipedia says that the cones are more time-sensitive than the rods, which isn't what I'd expect if that were the case. But that's what I experience. Maybe it was the result of the thing getting a sine wave --- which is what wall power would input to an LED --- rather than a square wave, which is (roughly) what I'd expect a system controlling brightness of an LED using PWM to output. I don't know what else would be unusual about that situation.
https://en.wikipedia.org/wiki/Flicker_fusion_threshold
Different points in the visual system have very different critical flicker fusion rate (CFF) sensitivities; the overall threshold frequency for perception cannot exceed the slowest of these for a given modulation amplitude. Each cell type integrates signals differently. For example, rod photoreceptor cells, which are exquisitely sensitive and capable of single-photon detection, are very sluggish, with time constants in mammals of about 200 ms. Cones, in contrast, while having much lower intensity sensitivity, have much better time resolution than rods do. For both rod- and cone-mediated vision, the fusion frequency increases as a function of illumination intensity, until it reaches a plateau corresponding to the maximal time resolution for each type of vision. The maximal fusion frequency for rod-mediated vision reaches a plateau at about 15 hertz (Hz), whereas cones reach a plateau, observable only at very high illumination intensities, of about 60 Hz.[3][4]
Passing an open hand with fingers extended in front of the light tends to make any flicker more visible, as it makes the moving fingers "judder", as with a strobe light.
The flicker fusion threshold does not prevent indirect detection of a high frame rate, such as the phantom array effect or wagon-wheel effect, as human-visible side effects of a finite frame rate were still seen on an experimental 480 Hz display.[6]
-
It's totally normal to perceive flickering at 60Hz
-
According to the above Wikipedia article, I don't believe it should be possible to see it with the rods at 60 Hz.
-
Tell that to my eyes lol. It's easy to see flickering of 60Hz on a CRT displaying a white screen.
-
With the rods of the eye. Your eye doesn't consist entirely of rods.
The Wikipedia article says that your cones should be more-sensitive to flashing at higher frequencies than the rods. The rods are what are what pick up light when you're viewing something through the corner of your eye. What I experience with these bulbs is the opposite of what I'd expect from that: flashing is noticeable and annoying when viewed in my peripheral vision, but gone (well, or on the edge of noticeability) when in the center of my vision.
EDIT: Well, to be fair, I guess I don't actually know that they don't have some sort of power control circuitry, haven't pulled one apart, so I guess I shouldn't say that they're 60 Hz. But unlike typical LED bulbs, they're narrow; these corncob bulbs don't have the bulge for space for an electronic ballast. If they don't have the ballast, I'd be expecting them to run off the wall power directly.
I wonder if I can go dig up a datasheet somewhere.
EDIT2: None of the technical material talks about any frequency of the bulb, but you might be right. There's one other thing power-control thing that you can stick in a bulb that might take up space, and that's a dimmable power supply. Like, if the wall power voltage drops, those will detect and reduce brightness. This one's non-dimmable. Maybe that's where the bulge at the base of LED bulbs comes from --- dimmer electronics --- and there's enough space to fit non-dimmable electronics up inside the body of the bulb.
EDIT3: No, it's not dimmability that determines the bulge. I see corncob lights with no bulge that are dimmable and corncob lights with a bulge that are not dimmable. But that also invalidates my reasoning above -- you have to have power regulation circuitry to make dimmable LED lights work, because that requires a variable-PWM source, and if it's possible to build dimmable bulbs with no bulge at the base, then I can't assume that no bulge means that LED bulbs are being driven straight off wall power without power regulation, which was my original assumption. Sorry, this is probably my error then. These are probably being driven by an electronic ballast at some frequency higher than 60 Hz, just still low enough to be within the range that I can still see.
-
Yeah that's still normal. Unless we're both just special. When looking at the center of a 60Hz CRT, the flickering is seen around the edges of the screen where I am not focusing. Or the whole screen if I look to the side of it. I also perceive LEDs flickering the same way you describe.
I'd guess the fact that we are not seeing it in our focus vision probably has less to do with physical attributes of the eye and more to do with the way our brains create our perception of vision. There's a lot going on there. Like our eyes are also constantly rapidly moving, and we are not conscious of or perceive that movement, there are 2 blind spots in our vision where our optic nerves connect to our retinas that we don't perceive, and our brain invents the color that we perceive in our peripheral vision, which cannot physically be detected by the eye. Vision is weird and complicated.
-
-
-
-
-
-
Most modern OLED panels on TVs and monitors don't actually use classic PWM for dimming, they never turn off completely and instead fluctuate between like 100% and 95% brightness based on the refresh rate.
Did you ever test if you can see that as well at different refresh rates?
rtings always tests this under "Image Flicker". https://www.rtings.com/monitor/tests/motion/image-flicker
It's not considered flicker-free but the OLED panels listed with 0 Hz PWM frequency (most of them) should look fine.
However, there are two other elements that might cause issues:
- VRR flicker
- ABL dimming in HDR
Both can cause an unpleasant experience if you are sensitive to it.
Phones still commonly use PWM because it uses less energy. There are some that have a DC dimming option but it's rare.
-
This sort of flickering can be really noticeable especially at low brightness, with the always-on display for example (although still nowhere near as bad as 60hz CRT flicker shudders*)
But I honestly do not believe thet you're able to see 4000+ hz flickering. If you genuinely can, I'm sure you could get a world record for that.
-
75 comments