I decided to get a new phone to replace my ageing Redmi Note 8 and settled on the Moto G54 which Notebookcheck passed as free from PWM. The first thing I did on powering it up was to test it with my own flicker detector and sure enough there was no sign of flickering from PWM. I did note some unusual spikes in the oscilloscope trace but I assumed they were caused by the screen refresh cycle, something which has never bothered me. Until now. Within a day of using it I noticed my eyes were starting to hurt which I did expect because PWM isn't the only thing about smartphones that hurts my eyes, default Android text rendering also gives me eyestrain. But the pain persisted even after I had corrected the text rendering and seemed to get worse even when just looking at an image or a blank screen without reading anything. Clearly something about the display, other than the text rendering, was hurting my eyes. Some kind of flicker was the most likely cause so I went back to the flicker detector for a more thorough inspection. Careful ajustment of the timing and amplitude of the oscilloscope revealed the following: First, for reference, the trace from my Redmi Note 8 on a static screen, this trace is indistinguishable from background noise. [upl-image-preview url=https://i.imgur.com/XQCWy1C.png] Now the trace from my Redmi Note 8 with the display being scrolled: now you can seem some undulations from the screen refresh cycle but they don't stand out very much from the background noise. This phone gives me no problems, even after extended use. [upl-image-preview url=https://i.imgur.com/qgp1yjS.png] Now the scrolling screen trace from the Moto G54: now we see clear oscillations with 3 or 4 times the amplitude as those on the Note 8 and at a higher frequency. [upl-image-preview url=https://i.imgur.com/gwUNOiW.png] Now the static screen from the G54: most of the trace is just background noise but note the cycle of spikes in the middle. These have the same amplitude and frequency as on the scrolling trace and the display flickers like that repeatedly even when the display content has not changed. [upl-image-preview url=https://i.imgur.com/iYbMQXq.png] Although it's difficult to draw firm conclusions, it seems that the screen on the Moto G54 flickers significantly whenever the display is refreshed and I believe that flickering is the cause of the eye pain I experience from using it. No changes I made to the display settings had any effect either on the amount of eye pain I got or on the oscilloscope traces. Setting the refresh rate to 60Hz, which is an option in the settings, had no effect on the oscilloscope trace, the display still flickered at the same frequency even though the refresh rate had clearly changed, evidenced by more smearing of scrolled text. I don't think that this is a software issue, I suspect the the flickering I have described is a property of the display hardware or the driver and is not, therefore, something that could be changed or fixed. I should add that both phones were running Android 14, stock Moto ROM on the G54, crDroid custom ROM on my Redmi Note 8. Has anyone else ever encountered this type of refresh-cycle dependent flickering?

The only one thing I noticed with less accurate Opple4 (than your device) - new laptop screens are more "noisy" (more pulsating), in terms of amplitude min/max state, even in "DC screen mode"

@"George357"#p39955 I also have the G54. When I bought it I used it for a few days with Android 13 and it was basically okay. But after updating to Android 14, looking at the screen seemed to be more stressing. Soon my eyes began to hurt. So I sold that G54 and bought another G54 which I left at Android 13, disabling all updates (also the updates of the main google apps). Since then it seems to be okay.

Having returned the Moto G54 I bought the next phone on my list of potentially usable phones, the Moto G34. After the disappointment with the G54, I approached the G34 more in hope than expectation and it has lived down to my expectations. Despite, like the G54, not showing any conventional PWM flickering on first inspection, the G34 made my eyes hurt after about an hour of use. A bit of fiddling with the oscilloscope settings revealed this: [upl-image-preview url=https://i.imgur.com/3nTC3bj.png] Like the G54, the display on the G34 flickers every time it is refreshed. Not as bad as the G54 because there is just a single up/down spike in the brightness rather than the sequence of spikes on the G54 and this display does not flicker continuously when it is scrolled like the one on the G54 but it still seems enough to give me eye pain. Setting the refresh rate to 60Hz helped a little but it only delayed the time at which pain set in. So, for me at least, the G34 is a failure and will be returned. Back to my trusty Redmi Note 8 until I can find something more modern with a truly flicker-free display.

Most touch LCD's operate like you see with the G34 and Redmi Note 8. I saw that way back with LG smartphones which had way lower amplitude during the scroll. Those sent three pulses after every single touch. Never bothered me at all. Your results with the G54 are not normal. Try max brightness + android's built in "night light" and "extra dim" turned on. That combo makes Moto feel great to me.

> @"George357"#p40244 A bit of fiddling with the oscilloscope settings Which oscilloscope you use? I like your results, very low itself noise

@"moonpie"#p40247 I tried all sorts of adjustments and settings on the G54, none made any difference. It always flickered as shown in my oscilloscope traces and the longer I used it, the worse my eye pain became. And whilst it may be the case that all LCD displays flicker to some degree due to the refresh cycle, the amplitude matters, and you can clearly see from the traces that on the G54 the flickering amplitude is far higher than on the Redmi Note 8. And I will reiterate: unlike the G54, my Redmi Note 8 gives me no problems, I can use it all day long and get zero eyestrain from it, no special settings or adjustments required. Also the flickering in trace 4 is not due to scrolling or touching, that was taken with the phone on the table not being interacted with at all. It flickered like that repeatedly whether being touched or not. As for your different experience with the G54, it is possible we are not comparing like with like. It is typical practice in the smartphone industry for manufacturers to use different displays during the production run of a given model. The Redmi Note 8, for example, was made with one of two different displays, one that flickers, one that doesn't. So it is possible that there are G54s out there that don't flicker like the one I had but no way to tell without testing a lot of them.

@"simplex"#p40259 It's not actually a 'real' oscilloscope, it's an app on my other phone displaying the output from a home-made light detector. The app is called NFX Oscilloscope Pro and it's very useful because you can pinch-zoom the display to adjust the scale of the x and y axes which makes it easier to get a clear view of the signal. It is also free and doesn't have any ads. No longer available on the Play store but you can find it on various download sites.

> @"George357"#p40262 home-made light detector Dont you find, all IPS have zig-zag measurments, its not possible to get "smooth horisontal" line ? Or it is equipment noise? I measure with opple4 last 3 panels for my laptop, all of them was DC dimming, but one have more smooth response, another has very zig-zaggy (very uncomfortalbe)… Or can it be pixel inversion? Mini light changes on the grapf

@"George357"#p40261 G54 should be avoided based on your reports. That is very, very bad. True that there may be different panel runs on the same model, but that G54 just looks like there is something beyond just the panel. I don't own G54. Moto Power and Stylus versions work fine.

@"simplex"#p40268 With my set up there is always some noise, as you can see from the oscilloscope traces, even where there is no actual flickering the line is not smooth or flat, it's jagged and although you can't see from the images, in real time the line moves up and down a lot. Maybe a proper, professional sensor and oscilloscope could generate cleaner results but what I have is good enough for my needs. And it was cheap! One check I always do is to move the sensor to one side so it can no longer pick up light from the display being tested. If the signal is real it should disappear and come back when the sensor is moved back in front of the display. Regarding the laptops you tested, I would say be careful of so-called DC Dimming, very often it is not what it claims to be and is just flickering at a lower amplitude or only at lower brightness settings. Notebookcheck has tested lots of phones with 'DC Dimming' and in many cases the result was not no flickering but merely less flickering or slightly less bad flickering which is not good enough, not for me anyway.

Eyestrain From Screen Refresh Flickering On Moto G54

Cirrus2709

moonpie It's the infrared sensor pulsations.

Cirrus2709

simplex One of the things i noticed is that the Moto G54 screen was much 'thinner' compared to the screen on the Zenfone 5 or Redmi Note 8. If you press or know it strongly, it sounds 'hollow'. The screens on the Redmi/Asus sound like thick glass when you know on them. Whereas when turned off, the former screens look black, this one looks somehow 'grey'. Its reflexibility under the sun is insane, it's just like a mirror. That ads onto top of the other topics.

George357

Cirrus2709 G45 is basically the same phone as the G34 with some very minor upgrades so expect it to have the same display as the G34 I tested above.

George357

simplex The G55 is essentially the same phone as the G54 with some minor upgrades, expect it to have the same display as the G54 with the same problems. Any hope for something with a different display will have to wait until the next generation.

simplex

George357 The G55 is essentially the same phone as the G54

Youre right, I found at least 2 bad feedbacks regarding G55's screen

simplex

George357

Can moto phones have intensive spectrums?

George357

Cirrus2709 I no longer have the G54 so can't test your theory about the IR LED but I am reasonably confident that the display flickering in my oscilloscope traces was the cause of my problems with it. Flickering displays are my main problem, along with Android's default text renderer settings.

Cirrus2709

George357

I wrote about this phone some months ago...

It has extreme reflectiveness due to a thin layer of glass (cost or weight saving measure or screen type I guess). Meaning, whatever flickers in the environment (and it always does, especially at night) you'll have it on your screen, despite the screen not having PWM per-se.

Second, the phone doesn't have a proximity sensor but uses the infrared one instead. Meaning you have an infrared light constantly pulsing into your eyes (just try it with your other's phone camera on slow motion anyone, it's next to the selfie camera).

https://youtube.com/shorts/jluXxsnftgU?si=5m3s_a7HfPcSLK6a

There you have it.

Besides, it has a poor outdoor brightness and no colour temperature sensor either, meaning there are 4 detrimental factors for the eyes, despite no having PWM.

To top it all, it has no brightness sensor either, using the selfie camera instead, making the auto-brightness mode extremely slow and/or inaccurate and necessiting user input/corrections most of the time.

Last but but least, some users reported that it has something to do as well with the MediaTek processor and their Miracast technology producing high-frequency flickering.

Btw it is a lot more usable in 60hz, neutral colours and with the infrared sensor disabled but all the other issues remain.

Cheers.

George357

simplex I don't know what that means.

simplex

George357

Old spectrums on the left ->

DisplaysShouldNotBeTVs

Cirrus2709 MediaTek processor and their Miracast technology producing high-frequency flickering.

Do you mean MiraVision? Miracast is just a device to TV casting protocol like AirPlay, you're probably thinking of MiraVision

ensete

Try enabling developer settings, then turn on "Disabling HW Overlays"

I still believe "flicker"/PWM is a red herring when it comes to display issues

fiftydinar

George357
I bought new OnePlus Nord CE 3 Lite in 9th January for 158 euros & I flashed LineageOS 2 hours after buy. It just got official LineageOS status in 4th January.
It works very well without any noticeable bugs in my usage, I like it (even VoLTE works).

It's flicker-free when I compare it with Poco X3 NFC, which had some flicker below 65% brightness. Nord didn't have any across all brightness range. But note that I didn't use some more professional tool to compare it, just a camera with 1/4000 shutter speed.

For me, I don't have eye-strain with it compared to Poco, but experience may vary.
It's the only new PWM-free phone I know which has custom ROM support.

George357

fiftydinar Thanks for sharing that. I've looked an Nord CE 3 Lite in the past but always decided against because there didn't seem to be any good stable custom ROM for it and the stock ROM seemed poor. With official LineageOS it's a more appealing prospect. Having exhausted almost all the other phones on my list of Potentially Usable Phones, I think I'll buy one and see how I get on with it.

moonpie

George357 I may risk buying and testing a Moto G75

NBC review is up:
https://www.notebookcheck.net/Motorola-Moto-G75-smartphone-review-Fast-waterproof-and-with-long-update-promises.945896.0.html

Definitely not as clean as Moto used to be. I think this is the year IPS dies.

George357

moonpie Thanks, I've read it. According to their review, no PWM but as we have found from the G54 and G34, that doesn't guarantee there is no flickering. The best we can do is to take the Notebookcheck review as a starting point for Potentially Usable Phones but to really know if a phone is flicker-free, you just have to buy one and test it yourself. But when even PWM-free phones have flickering we are entering difficult times. Will there ever be any more truly flicker-free phones?

moonpie

George357 True. NBC and laptopmedia are at best guides, not the gospel.

A truly flicker free screen would lack touch control. AFAIK, it's just HMD and I only see one model in USA:

https://www.hmd.com/en_us/nokia-2780-flip?sku=16WNDR11A01

The writing is on the wall. OLED and PWM is here to stay. I've given up chasing flicker free IPS smartphones. My time will be spent finding devices that closely replicate older "safe" OLED PWM screens i.e. Samsung S1-S9. Those were non-LTPO, fixed 60Hz refresh with a fixed low amplitude 240hz PWM.

S24 looks okay, but NBC doesn't test during touch and different refresh settings:
https://www.notebookcheck.net/Samsung-Galaxy-S24-smartphone-review-The-big-Galaxy-S24-inches-closer-to-the-S24-Ultra.811860.0.html

POLED's look okay below 25-50% depending on model:
https://www.notebookcheck.net/Motorola-Edge-50-Fusion-smartphone-review-Elegant-midrange-with-a-good-battery-life.857226.0.html
https://www.notebookcheck.net/Motorola-Edge-50-Ultra-smartphone-review-The-periscope-zoomer-with-a-huge-storage-capacity.859226.0.html

simplex

moonpie non-LTPO

Agreed. I also think, LTPS (a-Si) much better than LTPO / oxide TFT

qb74

George357
This is an excellent observation you've noted.
Every transition on your display may exhibit flicker / brightness oscillations.
This could very likely be a much larger culprit to eyestrain complaints than the software dithering talks on these forums.
Adding VRR (variable refresh rate panels) on top makes this even worse.

For example, desktop OLED displays have a ₂₅% brightness drop every refresh cycle (if 240hz display => every 4,17ms)
If you were to use it at 250cd/m2, it would drop by _80cd/m2 every 4,17ms (not a full on-off cycle, but on-semi off)

This is sadly an issue that very likely plagues a 99% of smartphone display models and even some desktop displays.
This can only be troubleshooted with proper G2G response times testing setup, using an oscilloscope and a good probe, the OSRTT or similar devices.

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