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?

Eyestrain From Screen Refresh Flickering On Moto G54

simplex

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"

Reinhard62

George357

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.

George357

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:

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.

simplex

George357 A bit of fiddling with the oscilloscope settings

Which oscilloscope you use? I like your results, very low itself noise

moonpie

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

moonpie 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.

George357

simplex 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.

moonpie

George357 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

George357 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

simplex 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.

Cirrus2709

moonpie It's the infrared sensor pulsations.

George357

PWM flickering on Fairphone 4. Having returned my G34 I invested in the next phone on my list of Potentially Usable Phones, the Fairphone 4. Other users here and elsewhere had described it as being 'comfortable' and flicker free and it was cleared as PWM-free by Notebookcheck when they reviewed it. Unfortunately, the one I bought has PWM flickering below 60% brightness, as shown in the trace below so Fairphone must have changed the display at some point. Above 60% it is flicker-free and with extra-dim turned on still flicker-free and dim enough for use in lit indoor rooms but maybe too bright for a darker situation. I'll probably sell it on and look for something else.

simplex

George357 I'll probably sell it on and look for something else.

I think, you need to limit searched phones by brightness range (upto +/- 500 nits). All extra brightness (800, 1000 nit), even in IPS, need PWM to adjust at any range (first part is DC-dimming, last part is PWM)

George357

simplex The conclusion I have come to is that truly flicker-free phones are even rarer than I thought. I believed, naively as it turns out, that since some manufacturers were still making LCD phones I would be able to get a more modern replacement for my Redmi Note 8, but it seems not. The need for flicker-free, combined with my need to have an unlockable bootloader, and preference for custom ROM support, limits my universe of Potentially Usable Phones to almost none. I may risk buying and testing a Moto G75 once the price comes down a bit but, given my experience with the G54 and G34, the chances of success are slim. I may still be using my Redmi Note 8 ten years from now…

moonpie

George357 Moto is it and their IPS has gotten worse at low brightness now:

https://www.youtube.com/watch?v=pul3o6sWcp0

simplex

George357 buying and testing a Moto G75

no, it is bad as G54 model. Dont waste money for it

I am wait for G55 positive reviews now

btw. can it be something bad in modern TFT sandvich? light diffuser ? another type of LEDs, which have similar RGB peaks but some extra peaks in UV zone which is not detectable with standart optical meters range (400-750nm) ?

Cirrus2709

George357

I am sticking to Zenfone 5z for now, it's the most eye-friendly i've been able to find with unlockable bootloader. It's an older device but not slow by any means, it has good cameras and the best audio i've ever encountered on any device.

Another reason/issues that i've encountered with Motorola G54:

- Besides being very reflective, the screen brightness is low, which makes things even worse and makes the contrast to plummet; it's about 20% lower than some other phones but the difference is extremely noticeable. This phone bothers me more during the day than at night, where it's impossible to find the right level of luminosity and screen temperature.

- the ambient light sensor is extremely slow or of extremely low quality. Whereas the Asus would change the light level near instantly, it takes the Motorola about 5 seconds to start lowering/increasing the level of light making it very uncomfortable to the eyes. Even then, it's rarely on point and even after a week of use (when the phone should have learned my preferences) i still find myself very often regulating the slider manually.

- another point; this phone doesn't seem to have a light temperature sensor. This might be the worst thing about it. You're stuck between two options, 'natural' and 'saturated' which both seem unnatural and which work only under extremely light conditions. In all other, including indoors, cloudy, the screen colour temperature is totally out of touch and can't be changed either through the sensor (there is none) or manually the options are extremely limited and basically represent a choice from bad to worse.

So even if the screen/display on the G54 might be good on paper, it lacks the adjoining technology for it to work. Besides, it reflectivity is beyond any phone i've ever used. It's like a mirror. I don't know about the recently announced G64 but i've heard that even the flagship Motorola Edge plus doesn't have a physical light sensor but uses the selfie camera instead, which is apparently unable to display/affect and adapt to the ambient colour temperature (or even luminosity), making this screen ultimately worse than some AMOLED panels with DC dimming and good ambient light/colour sensors.

For me this screen is worse than the one i had on the Asus ROG phone 5 which was AMOLED but had DC dimming and could be calibrated manually as well.

That's in short.

Cirrus2709

George357 Besides, i forgot to add.

The Moto G54 has no hardware proximity sensor.

Instead of, it uses an infrared pulsating LED that i've been able to detect with my other phone in manual mode.

If the LED is disabled and colour conditions set to 'natural' the screen becomes 'usable', at least at night.

But then, you don't have touch to wake up and other gestures, as well the gyroscope (no auto-rotate mode) and other movement sensor related functions.

https://www.youtube.com/shorts/jluXxsnftgU

I'd say that flickering LED produces 50% of the eye strain.

Cirrus2709

simplex Any experience guys with the G45?

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

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.

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

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.