Usable Smartphones?

Seagull

From what I have seen of testing of DC dimmed oled screens, they still kind of flicker. I often see a 60hz dip in brightness on oscilloscope outputs. I presume its an artefact of updating the current frame to the next. Owing to OLEDs being an emissive type of display, any interruption in output as a pixel updates will result in flicker. I tried an old LG Flex 2, reported to be PWM free but still had problems with it.

KM

I think that 60 Hz flicker is a scanline. Should be easily revealed with not 1 but 2 oscilloscope probes and then looking if there's a delay between top/bottom of the display.

Maxx

With a DSLR the OnePlus flickers like mad still with the DC dimming. The black band that passes the screen is like 1cm think in lower brightness settings. So the DC dimming is just a decoy or a hoax for us who are sensitive to PWM. For me the PWM sensitivity is such that even at 2300 Hz with the Sony Xperia ZX I get bloodshot eyes in 30 min if I let the brightness dropo to under 35 %. So somehow my optic nerves are still able to sense even the very high 2300 Hz flicker. And why not? Ears are able to sense a "flicker" of 20Khz. E.g. dogs are able to sense ultrasonic sounds much higher than that, so why would the optic nerve not sense flicker of 2300 Hz. It's a different thing then what the body does with this information that it senses. Most people don't get any noticeable symptoms.

Maxx

But the curious thing is that what is causing the eye strain in the displays that are measured with a high sensitivity oscilloscope to be flicker free? My guess is that it is some sort of dither, because I'm completely unable to use my Surface Laptop that is flicker free. I'm again guessing but I kinda feel like I would see something like "snowing" effect of the analog TV's in the surface screen and also with the Nova 5t.

But what amazes me even more, is that I've talked to at least 10 eye doctors and a neurologist over the years and each one of them either thinks that it's all in my head or that I have dry eyes. Yes, I might have dryer eyes on top of the flicker sensitivity, but I ha absolutely ZERO problems with my eyes with displays that do not flicker and do not have, what I assume is the dither like with Surface devices. The Lenovo laptop at work is perfectly OK, my HPZR2740w display is completely OK. My Sony Android LCD TV is OK. I cannot use any OLED device, not even the televisions which show only like a 1mm think band with a DSLR passing at 120 Hz.

I don't know if anyone has noted this about themselves, but I seem to have much quicker reflexes than most people. Say an input lag test (you can find one by googling) I'm much faster than anyone I've tried it with. So maybe there is something in my nervous system that is "tuned" to notice things that flicker faster than others, that might be a factor that affects the ability to sense flicker of high Hz.

Seagull

Maxx

In my experience, doctors would much rather give a weak diagnosis than say I don't know. Despite the later being much less harmful.

degen

The DC dimming works, it's just the devices have so many other problems like OS and GPU induced strain. If removing PWM were the cure, we would all be on the many LCD-based iPhones for years now.

Maxx

degen sorry degen, but you are wrong. DC dimming absolutely does not work. It still flickers like PWM in notebookcheck. net tests and is easily visible with a DSLR. For me, PWM is Most of the time the only issue. Most of the time if I can not detect any flicker with DSLR, then the display is OK, like my new sony android TV and many other devices. In fact, now I can confirm that even the Nova 5t seems to be OK, my eyes were just so irritated from Oneplus DC dimming that I thought that the Nova is also irritating.

Of course, if Oneplus DC dimming would actually prevent all PWM type flickering, then there might still be the similar source of eye strain that is with the Surface devices, but we can't test this as the PWM remains the main source of eye strain even with DC dimming.

Maxx

degen Sorry degen, you just are plain wrong. For my eyes, a flickering screen is not ok under any circumstances. DC Dimming flickers just like PWM when taken a video with a DSLR

Maxx

Maxx It would be a different scenario if there would be even one single display with PWM that I could tolerate. But that is not the case. PWM = eye strain and DC dimming = PWM

KM

Something must be wrong if stripes are visible while using DC dimming. It seems the function is not working at all in your case. The 60 Hz flicker shouldn't be visible in the form of black stripes. If at all, only very, very faintly.

Maxx

KM With DSLR at 4000 shutter speed in video or even in photo it is. And it does flicker less when switching dc dimming on, so I doubt anything is wrong per se, it is just not the solution for PWM. Noteboocheck also have confirmed that dc dimming does flicker.

degen

Maxx

I'm looking at that article which highlights the OnePius 7 Pro DC dimming feature on notebookcheck and it is flatline on their oscilloscope. The 60 Hz flicker remains but that is seperate.

Maxx

degen It is not flat line, there is the 120hz small (or 60, not sure) small dip which is flicker. For me it is enough to cause eye strain. And I did test the flicker with my DSLR, I could post a video about the flicker if I would feel inclined to prove this, but I don't need. You can have your own opinion about the flicker of DC dimming, but the fact remains that it flickers and that that is the primary source of eye strain. I want to stress that I does not help that false information is spread. DC dimming will not be a solution for those who are sensitive to PWM.

Maxx

Maxx Reporting back that the Nova 5t is not usable long term. Eyes still fried, even tough I did not use the phone that much yesterday. So then it's similar to Surface devices. No PWM but still causes eye strain. Nova 5t uses a Ltps display, which could be the reason, but I did have the same issue with Huawei mate 9, it was also no PWM and but an IPS display, it caused terrible eye strain. So maybe Huawei uses some dithering to make their IPS displays look better. Back to my Xperia xz premium, that has been problem free for 2.5 years.

KM

Maxx I want to stress that I does not help that false information is spread. DC dimming will not be a solution for those who are sensitive to PWM.

Well it helps me for sure. My OnePlus 3 has what they now call DC dimming at a certain brightness level and above. If I go below, long-lasting eyestrain within seconds, and red eyes. So it is a solution for me. I think you can call me PWM-sensitive if the eye strain kicks in within seconds and then lasts for hours.
The 60 Hz brightness dip is so small it is barely visible with a camera.

I think if your device has obvious stripes when viewed through a camera, the 60 (120?) Hz brightness dip must be unusually strong. So further investigation could clarify this.
There is a chance this varies between models or even the same devices. But no one has looked into this yet. I can imagine if the dip goes too low, it could trigger PWM symptoms.

Seagull

Maxx I do believe you, but as a sanity check, you have turned on DC dimming in the settings? (iirc it has to be turned on)

Maxx

yes. I could post a picture from my DSLR with a thick black band from the screen where it says dc dimming enabled. This flicker is worse than in OLED tv's, which I also cannot tolerate. I've had 2 of them at home for a few weeks, but the flicker just irritates my eyes.

Interesting that this whole problem is such that most people not to mention doctors cannot believe or understand it, even when they see the bloodshot eyes, so when the discussion on this forum revolves around trying to prove constantly that some display is problematic to the people who have the same problem, just amazes me.

diop

Maxx My once usable iPhone 6S became extremely uncomfortable to use after I updated to iOS12 from 10.3.x.

It might not necessarily be the display to blame, but the OS rendering/dithering. Unlike a PC we can't chop and change hardware/software on a mobile device (easily) so it could be the panel, or it could be the software.

Maxx Interesting that this whole problem is such that most people not to mention doctors cannot believe or understand it, even when they see the bloodshot eyes, so when the discussion on this forum revolves around trying to prove constantly that some display is problematic to the people who have the same problem, just amazes me.

I guess we all have different tolerances to PWM, or it effects us differently. Nethertheless I don't like the idea of PWM in principle due to it essentially turning a display into a strobe light.

Also most mobile devices have a huge blue light spike, I hope the industry tackle this soon as it's inexcusable. I heard a news report recently stating approximately 40% of kids and teenagers have difficulty sleeping, perhaps due to excessive blue light exposure from phones.

Maxx

Yes, that's what I've found too. I've tested several laptops and phones that do not have any sort of PWM, but still cause exactly similar symptoms as PWM. So yes, that is true that there is some other form of flicker present like dither or something similar. But with the DC Dimming on OLED's we cannot even go past the PWM when the DC Dimmins IS PWM, just a slightly milder PWM. But for me, PWM has always been a problem. Even with CTFL computer displays where the PWM is much less abrupt, I always got the symptoms, though it took more time to experience. So even a milder form or strobo light will cause eye strain for me.

Now it would be critical to understand why Sony Xperia XZ Premium has been completely problem free for me during the past 2.5 years I've used it heavily if it is >35% brightness and Huawei Mate 9 and Huawei Nova 5t are not, thought both of them have and LCD display and no PWM. So what technology is in use in those displays that is not used in the Sony display.

I'm now trying to source second hand XZ2 premium to see if the display is also OK like XZ, as I do want to have a reasonably modern smartphone that I can use.

It is just a mystery why this problem does not seem to gain any meaningful momentum. Nowadays most phones seem to be OLED and I can't seem to find an LCD phone which would not have the dither or some other tech that is causing eye strain anymore. I fear that soon there simply is no devices that I can use. Really, then I just need to stop using a smartphone and that will affect my work considerably and other life, too.

Over the years I have commented on this and other forums that my XZ Premium is problem free, but when it was still available in the shops, nobody from this forum seemed to try it out and report back "hey, I also bought it and it does not irritate my eyes" So why people who have this issue are not bothered to get a device that has been confirmed problem free and why we do not seem to have any reports in this "usable smartphones" thread where the somebody would list a recent device that is problem free like XZ Premium.

There are still some phones that do have a PWM free LCD or at least in higher brighness levels, why nobody has them and reports back?

Sunspark

Maxx It's because it's too hard to zero in. Gurm and I can both use devices with PWM even tho we might not love it and it is more tiring than ones without it. The Sonys use triluminos and some don't like that. I don't have a problem with spatial dithering but don't like temporal dithering. Then there is font rendering and other factors like contrast ratio, colour temperature, subpixel arrangement (RGB vs pentile) etc. Overall, I do think things are getting better slowly as more options become available like the Hisense e-ink device (which only 1 person here purchased that I am aware of).

I also need reading glasses now and I haven't gone in for a prescription, which is part of why I have started leaning toward larger devices.

Too many variables.

Edit: Incidentally, as of the last while with the exception of watching videos, I have actually had the brightness turned down quite low on my A70 down into the visible PWM zone along with the blue light filter turned on at the midpoint setting. I find it easier to view text when it's duller and more gray than when it's glaringly white. At full brightness I turn the filter off.

degen

Sunspark I forget why you don't use OLED Saver. It made text harder to read I think? And why do you think that is? If you can elaborate again I would appreciate it.

Sunspark

degen Something like that, because the device would still be on full brightness but the app would be overlaying a software layer of gray on top of the rendering. It made text less defined. We're not talking a lot, but on pages on desktop mode with small font sizes it was noticeable. It wasn't bad or anything, just didn't seem to give enough value in exchange for more battery consumption.

What needs to be done for a proper implementation of it is to have the app or system settings be permitted access to the kernel itself much like cf.lumen can do with a supported kernel, or rooted. My device has neither. The app also appears to be abandoned now. Likewise cf.lumen is also abandoned now and doesn't work on my A70 even in software overlay mode.

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