Database Develop

Screen flicker (PWM)

I still use the original Note, and I really like the Note 4, but the screen flicker and color shift is making me hesitate about upgrading, because it's partly a downgrade.
If you don't know what screen flickering is, it's when the light from the display is more like a strobe light than a flash light. That is how many displays lower their brightness.
Think of it like a water faucet. Turn it on full blast, and that's the light from the LED at the brightest setting. To make it darker, you'd close the faucet a little, and less water would flow out. Or you could rapidly turn it on and off, and less water would also flow out, but it'd be in spurts.
The original Galaxy Note is like the normal water faucet, where it's a steady stream at full brightness, and as you lower the brightness it simply decreases the force of the steady stream.
The Galaxy Note 4 is like the water faucet that is constantly turning on and off in spurts, even at full brightness. Then as you lower the brightness, it leaves the faucet off longer, so less light comes out over time, and it appears darker.
Why does this matter? Because, a constant steady stream is pleasant, and a jolting repetitive spurt is irritating.
The original Galaxy Note is like a seamless line, and the Note 4 is like a bunch of -----------.
Galaxy Note 4 at maximum brightness (240 Hz):
Code:
-------------------------------------------------
Medium brightness:
Code:
- - - - - - - - - - - - - - - - - - - - - - - - -
Low brightness:
Code:
- - - - - - - - - - - - - - - - -
You can see this on some of the video reviews. It's most noticeable when they have the brightness lowered, and are on a bright white screen. You will see diagonal lines cycling across the screen like waves.
Try this... lower the brightness of your display to the minimum, and go to a white page. Then wave your open hand in front of it. Do you see a normal motion blur like when you do it away from the screen, or do you see a bunch of sharp lines, like trails from a strobe light?
Different people can perceive different rates of strobing light, and some are irritated by it quicker than others. But everyone should prefer a steady stream of light over an abrupt pulsing one.
There's more info on these pages:
tftcentral.co.uk/articles/content/pulse_width_modulation.htm
en.wikipedia.org/wiki/Flicker_%28screen%29
en.wikipedia.org/wiki/Flicker_fusion_threshold

best wait till the Note 5 maybe even the Note 6

It was already brought up here http://forum.xda-developers.com/note-4/general/request-to-samsung-flickering-t2905055 but moderators closed the thread. Sigh.

why Mod closed that thread?

Anyone know if there's any control over the PWM in software? Does Samsung release the display driver code?
With regular LCD displays there might be a kernel driver (drivers/video/backlight), and a sysfs entry (/sys/class/backlight/brightness). But with AMOLED they are using PWM to control the brightness of each sub-pixel, not a panel backlight.
With luck maybe at least there's an interface that could instruct the hardware to not use PWM at maximum brightness. I'd guess all the color calibration adaptive display technology would have to be bypassed though.

The PWM is defined in the kernel driver and it's too complex to change it.

I have a Note 3 and have never noticed anything like this. Does this affect the Note 3? I can't imagine why the Note 4 would do this if the Note 3 didn't. Why take a step back?
Sent from my SM-N900T using XDA Premium 4 mobile app

You know that video recording exaggerates the effect by miles? And your light bulbs flicker in a similar way? The frequency is too high for your eyes to notice though so it doesn't matter.

I found a video that compares the Galaxy Note 3 and 4 side by side. The PWM frequency looks similar in auto mode. But notice how when he changes them both to maximum brightness the Note 3 doesn't flash like the 4 does. For some reason the Galaxy Note 4 flashes all the time, even with full brightness.
youtube.com/watch?v=bHBLA0txReg#t=521
(Fast forward to 9 minutes)
Light bulbs can strobe too, and some people are sensitive. Have you ever been sick and went to a store or office with fluorescent lights? Maybe you've noticed the lighting isn't as comfortable as natural lighting. Sometimes it can make people feel disoriented, like trying to walk through a strobe light.
It would be reassuring if someone sensitive to PWM lighting said that the Galaxy Note 4 screen isn't a problem for them, even after several hours of reading.

screen flicker
Hello,
I have only used iphone since the iphone 3. I preordered the note 4. I researched alot and hope this is not going to be too big. But through my research came about this video and don't know if this is a solution your looking for but may help.
This is my first post and not allowed to link the youtube link.
Search reduce amoled flicker the video was only posted 5 days ago. Hopefully this is a good solution

This one? youtube.com/watch?v=gQNcaa2EV2U
The idea behind that is to set the brightness to maximum so it doesn't use PWM, then put a semi-transparent black layer above everything to make it appear darker.
That could work with other phones, but the Galaxy Note 4 is reported to always uses PWM, even at maximum brightness, so even with that trick there will still be strobing at 240 Hz. That might be better if the frequency would otherwise be real low at the lowest brightness.
But I think there could be other problems, like higher battery usage, rendering artifacts, inaccurate colors, and slower framerates, caused by having to recalculate all output with the transparent layer on top.
I also wonder if that even works the way they expect. If the AMOLED sub-pixels are changing intensity via PWM that is independent of the master brightness, then maybe applying a semi-transparent layer would cause those darker sub-pixels to darken by decreasing the frequency, which would be similar to lowering the master brightness level.

Noterio:
If you can see flicker of amoled displays, simply get an lcd one.
I've owned S2, S3, and S4. And never saw any flickering, especially in the darkness.
The effect on video is simply a mismatch between the framerate of the video and the refresh rate of the screen.

Many LCD displays also use PWM, but for the backlight instead of the sub-pixels. It's a similar strobing effect. I have a desktop display and tablet that use PWM, and I have to set them at maximum brightness to avoid the strobing. I've used them with low brightness for many hours and days, but it feels like staring into a strobe light.
Not everyone is sensitive. It's like, some people watch standard definition on an HD TV and don't understand why you think that's crazy. If you show them HD on the display, they act like there's not much of a difference and can continue watching SD. Other people notice smaller details and it would be too annoying to watch SD like that.
The Galaxy S4 does strobe too. I'm sure if you pay attention you can find ways to see it. One time I often notice PWM the most is when I'm staring at the screen, then look to the side. As I look to the side real fast, in my peripheral vision the flashing screen has a trail effect like when you wave your hand in a dark room lit up by a strobe light.
You could also probably set the brightness to lowest, and swirl it around in a dark room. If you move it fast, and watch the light, you'll probably see it's not a smooth blur, but has sharp jagged edges from the points in time when the pulse bursts to higher brightness.
You can also wave a pen in front of the screen and see the strobing effect.
If you don't ever notice or feel the strobing, then it's fine for you. Just like some people are fine watching SD on a very expensive TV. I don't like having to pay around $800 for a display I'll be looking at for hours every day if it's going to be irritating sometimes. Especially since it flashes even at maximum brightness, so there's no tricks to avoid it.
The fact that most people don't notice or care means there's little incentive for the manufacturers to spend extra money to avoid strobing.

more videos with flickering
note 4 (new video)
http://www.youtube.com/watch?feature=player_embedded&v=UMPfGki0Hcs
others
https://www.youtube.com/watch?feature=player_embedde%85amp;v=amuHUv6hGiM
http://www.youtube.com/watch?v=paMb_cgVkug&list=UUB2527zGV3A0Km_quJiUaeQ#t=869
http://www.youtube.com/watch?v=fQdvK5-Ejag
http://www.youtube.com/watch?v=kKCIuZsp_VQ
http://www.youtube.com/watch?v=dxtItMajHfg
http://www.youtube.com/watch?feature=player_embedded&v=8U6iuzhrgaA
http://www.youtube.com/watch?feature=player_embedded&v=aeDvaMZ8Uxo
http://www.youtube.com/watch?v=EzMdvFUhOW4
http://www.youtube.com/watch?v=FgUgN5S4C0s
http://www.youtube.com/watch?feature=player_embedded&v=fQdvK5-Ejag
https://vimeo.com/101804094
tests (use google translate)
http://www.ixbt.com/mobile/samsung-galaxy-s5.shtml
http://www.ixbt.com/mobile/samsung-galaxy-note4.shtml
http://www.ixbt.com/mobile/samsung-galaxy-note3.shtml
http://www.ixbt.com/mobile/samsung-galaxy-note2.shtml
http://www.ixbt.com/mobile/samsung-galaxy-s4.shtml
Just need to make the frequency of PWM like in Fly IQ444 Diamond 2 Quattro, Motorola Razr HD and lg G Flex

See how the Note 3 has the screen on most of the time at max brightness?
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The Note 4 looks worse out of all the Notes and S series, because even at max brightness it is abruptly flashing.
Maybe someone can test different settings while looking at the Note 4 through their camera to see if anything affects the PWM.

noterio said:
The Note 4 looks worse out of all the Notes and S series, because even at max brightness it is abruptly flashing.
.
Click to expand...
Click to collapse
It does not matter, the main thing that the chart does not dropped to zero. Harm to the eye and brain (at long view) occurs when there is a full damping.

I had this issue with s4 running factory set rom, after a day or two of purchase I got an update which resolved this issue. Future updates will take care if this issue if it is present at all

The PWM isn't considered a defect, so I'd be very surprised if they changed it in a firmware update.
The big question is at what brightness setting would the graph show it cycling to zero? If it's already dipping below half brightness at the maximum setting, then that's already close to a full strobe, so if you set it to 90% brightness will it be going to zero like 50% does?
Someone should look at it through a camera so they can see the flashing better, and watch to see at what brightness setting it starts to be worse.

Have mine for a day now, up late last night messing with it. Flickering a non issue for my eyes, so glad.

That's good, but has anyone done anymore technical testing? How low can the brightness go before the strobing is more obvious in a camera viewfinder? Has anyone posted any videos of a slow transition from max to min brightness?

Burn in concerns?

Until now, I've actively avoided AMOLED screens, in part due to the ability to get screen burn in. I'm still not thrilled about it, but it seems no flagship has LCD anymore and I'll have to make the trade-off.
I get some of the benefits of AMOLED, but this surprised me a bit to find on a gaming phone since games have static images (scores, gauges, maps, icons, etc). I also know that running an AMOLED at full brightness increases the burn in risk, but I'll be using this daily in bright sunlight and will need the screen fairly bright.
So what's the current expectation for the ROG 2 screen when it comes to that? Any word on if burn in will be much of a risk anymore? Would the Asus U.S. Warranty cover that, and for how long?

Burn in is probably a far smaller issue than you'd think. I've used AMOLED displays since 2010 on several different devices and never had an issue. It does happen but probably far less common than you'd think.

The only AMOLED device I've had that experienced burn in was a Samsung Galaxy Note 5, which I used for many years and was my daily phone up until I received this ROG Phone 2 a week ago. Even then, I didn't notice the burn in on it until about a year ago, and only found it by deliberately looking for it by using an app to show full screen solid colors. Even to this day I don't notice the burn in on that Note 5 during normal use. The entire time I used the Note 5 I had the brightness set to max with adaptive brightness on.

willhemmens said:
Burn in is probably a far smaller issue than you'd think. I've used AMOLED displays since 2010 on several different devices and never had an issue. It does happen but probably far less common than you'd think.
Click to expand...
Click to collapse
Especially with gestures replacing the static nav bar. Those would burn in over time. But the status bar stays pretty active, so there shouldn't be much chance their either

bluegizmo83 said:
The only AMOLED device I've had that experienced burn in was a Samsung Galaxy Note 5, which I used for many years and was my daily phone up until I received this ROG Phone 2 a week ago. Even then, I didn't notice the burn in on it until about a year ago, and only found it by deliberately looking for it by using an app to show full screen solid colors. Even to this day I don't notice the burn in on that Note 5 during normal use. The entire time I used the Note 5 I had the brightness set to max with adaptive brightness on.
Click to expand...
Click to collapse
My wife prefers the Notes and every one of hers got burn in. Her last one was the S7 (due to the N7 fiasco), and I noticed burn in within a year. She rarely has the brightness cranked, which is part of why I'm still on the fence.

Now that I have android auto radios in all my cars I don't expect to get much burn in from now on, but my note 8 always has Waze ghosted on the screen.
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As others have mentioned before the benefits of Amoled screens far out take the LCD ones in many areas. For example one thing I hated about LCD screens because of the technology was the uneven side/bottom light spots which can be easily seen in a dark room and were very annoying to see.
Regarding Burn in, there is an easy way to avoid it in the long run by using gestures for system navigation and in regards of the status bar you can use any 3rd party app which can hide the status bar. Personally I use "Immersive manager" app to hide the status bar on ASUS launcher and in some apps which I don't like to see it in, and so because of the switch between the home screen and apps, the status bar isn't static and for that reason i doubt burn in will be an issue.

I would caution about the "Always-On Display" option of the Asus Rog Phone 2. If you go to bed and leave the phone face-up (proximity sensor not covered) then it will leave the static clock graphics up all night. I could imagine that being burned in over time.

RogPhoney said:
I would caution about the "Always-On Display" option of the Asus Rog Phone 2. If you go to bed and leave the phone face-up (proximity sensor not covered) then it will leave the static clock graphics up all night. I could imagine that being burned in over time.
Click to expand...
Click to collapse
I was watching a review video on it yesterday and it showed what looked like the AOD clock shifting (it was a short cutaway shot, so could be mistaken). I will keep an eye on it, though, to see if it does move.

Just like you, I avoid AMOLED screens. I had an S3, burn ins from web browser... I watch YouTube a lot. I am not sure the AMOLED screen is for me. It became difficult to choose a phone.

SchnauzerZoom said:
Just like you, I avoid AMOLED screens. I had an S3, burn ins from web browser... I watch YouTube a lot. I am not sure the AMOLED screen is for me. It became difficult to choose a phone.
Click to expand...
Click to collapse
Just enable Dark Mode within YouTube and assuming you watch in full screen mode, you should not have any problems. I personally run YT for about 3-4 hours everyday: the phone sits below my monitor at work and I have earphones on. Glance at the screen from time to time, since what I usually do doesn't require full concentration at most times. Never faced burn in from YouTube.
I did face some issues on Quora though, but that was with a Moto G4+ and seemed to be temporary. The logo bar on top stayed for a while, ghosting as I used other apps but went away in a few minutes after I left the page.

Amoled screens burn-in is much less likely to happen now due to advancement in screen technology and also software implementation to counter it.
There used to be a time when averagely 30-40% of screens had a form of burn-in or another.
Unless you're unfortunate to get a defective screen, I doubt if burn-in will be an issue for you.
I have a 2-year old Huawei Mate 10 Pro which I've used so much and mostly outside (full screen brightness), but there isn't a sign of burn-in on it.
Though it would be important to know the screen manufacturer for the ROG II as not only you can have an idea of the quality but also aesthetics.

I already have some lines and screen uneveness in lower brightness and mostly gray color, i wouldnt call them burn-ins but the device screen is diffinitely defective as it's only 4 weeks old and the screen was uneven from the beginning
Btw the quality and sharpness of colors is nowhere close to my father's galaxy a40 so either my device is a complete defect or the screen is just not that high-end stuff
And lets not forget the rediculous issue of getting red tine when lowering the brightness it sometimes drives me crazy, still the 120hz refresh rate is so great i cant think about any other phone!

Red tint on dark grey ie dark theme on brightness below 50%

There is a noticeable red tint on dark grey color everywhere while the brightness slider is set in range of 0-49%. Effect is more pronounced while using 120hz refresh rate and less while using other modes. 50% and above and the tint just disappears.
Does anybody suffers with the same issue? This is indian variant of the phone.
Attached image can be used for testing.

This seems to be a problem with many ROG 2 owners. The Red tint is massive at low brightness. And yes, this is a screen problem not a software issue.
Better try replacing the unit. But there is no guarantee new phone won't have the same problem as many people are reporting this issue.
I think maybe Asus is buying cheaper display from some other manufacturer, not Samsung. Here is a similar complaint thread on Asus forums -
https://zentalk.asus.com/en/discussion/11085/display-red-tint-issue-on-my-rog-2
And if it very troublesome for you, simply return it, ask for refund and buy some other device.

I will probably do that but samsung has that stupid hole. I sold my op 7 pro for this.
But 1 thing that is interesting is at 60hz the red tint is visible at 0-10% range. And the higher the refresh rate the more brightness range it covers like at 120hz its visible at 0-40% range. At 50% nothing of such sort is visible at any refresh rate.
It mostly has to do with that 1ms gtg ie grey to grey response time at high refresh rate. And yes all units will have that issue maybe not at 60hz but definitely at 120hz.
Lets see if asus has any response. I still have my return window left.

And now you know why others don't have 120Hz AMOLED panels, and why reviewers complain about the minimum brightness being too bright. Asus tried to mitigate these issues because the panels are only acceptable above a certain brightness.

I have an Indian unit and have the red tint. I don't have an issue as i keep my screen at 50% brightness. Hope in Android 10 apps use black instead of dark grey for the dark mode

madsud said:
I have an Indian unit and have the red tint. I don't have an issue as i keep my screen at 50% brightness. Hope in Android 10 apps use black instead of dark grey for the dark mode
Click to expand...
Click to collapse
Reality is that most apps including google ones are going the way of dark grey background, not pure black.
Also always 50% brightness? Don't you turn it down in room with no lights or low lights?
---------- Post added at 08:29 AM ---------- Previous post was at 08:13 AM ----------
sanurocks said:
I will probably do that but samsung has that stupid hole. I sold my op 7 pro for this.
But 1 thing that is interesting is at 60hz the red tint is visible at 0-10% range. And the higher the refresh rate the more brightness range it covers like at 120hz its visible at 0-40% range. At 50% nothing of such sort is visible at any refresh rate.
It mostly has to do with that 1ms gtg ie grey to grey response time at high refresh rate. And yes all units will have that issue maybe not at 60hz but definitely at 120hz.
Lets see if asus has any response. I still have my return window left.
Click to expand...
Click to collapse
You sold OP7 Pro for this? Seriously bro? I mean unless one is a gaming fanatic, ROG doesn't make sense for someone who wants a overall great experience. It was evident that Asus has cut corners at many places when they priced it so low.
Even if it's 60Hz, red tint shouldn't be there. It's an example of not a good display.

Abhi Dahiya said:
You sold OP7 Pro for this? Seriously bro? I mean unless one is a gaming fanatic, ROG doesn't make sense for someone who wants a overall great experience. It was evident that Asus has cut corners at many places when they priced it so low.
Even if it's 60Hz, red tint shouldn't be there. It's an example of not a good display.
Click to expand...
Click to collapse
OP7 Pro had its issues, I bought it on first sale. camera focus was not good, camera output was soft around corners while clicking text/documents for sharing. the screen though gorgeous looking was actually hard to use. i can recall a particular issue - i use phone pe and the menu for edit beneficiary was just in the screen space where it started to become edge and it required multiple touch to activate it.
actually rog 2 feels more premium in hand and the weight distribution is quite good as compared to op7 pro, it was top heavy. i have large hands so actual phone size was not the issue with either op7 pro or rog 2.
if one can ignore this red tint issue almost every aspect is better than op7 pro. screen above 50% brightness( which is actually not 50% screen brightness output, its just 50% slider) hdr in video playback works very well, its a quite brighter than op7 pro. Sharpness is less but only apparent on close viewing. Sound quality is better on speakers and louder too. Screen smoothness is much better. gets less hot then op7 pro, Cyber hunter on full was 47-48 on op7 pro, its 44-45 on rog ii. and the battery life is way better. There are much differences to be pointed out but the thread will grow.
Though the phone might not look professional in a meeting and i don't think it will receive timely android updates. But as a usable device i find this better than op 7 pro. If the grey management was not an issue this would have been almost unbeatable in its category and even in a higher category. op7 pro costed me 51.5k after bank discount, this costed 34k after bank discount.

Abhi Dahiya said:
Reality is that most apps including google ones are going the way of dark grey background, not pure black.
Also always 50% brightness? Don't you turn it down in room with no lights or low lights?
Agree. Said just a hope. The objective of dark mode is also to take advantage of amoled which is not met by grey. Hoping common sense prevails.
I hardly use the mobile in low light, if i do, i dont turn the brightness down
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Click to collapse

I'm swapping my Galaxy S8 in for this. How certain are we that this red tint is a hardware issue?

GeekGod said:
I'm swapping my Galaxy S8 in for this. How certain are we that this red tint is a hardware issue?
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Click to collapse
Definitely a hw issue. Its only notcieable between 15 to 30%. I wouldnt worry about it.

madsud said:
Abhi Dahiya said:
Reality is that most apps including google ones are going the way of dark grey background, not pure black.
Also always 50% brightness? Don't you turn it down in room with no lights or low lights?
Agree. Said just a hope. The objective of dark mode is also to take advantage of amoled which is not met by grey. Hoping common sense prevails.
I hardly use the mobile in low light, if i do, i dont turn the brightness down
Click to expand...
Click to collapse
If you wanna see the issue:
1) go to a dark room or in a room with almost no light.
2) add "Screen Frequency" toggle in the status bar, and lower the status bar to show the toggles;
3) lower the brightness above 40-50%;
4) use the toggle to swap frequency from 60Hz, 90Hz and 120Hz.
You will notice the colour of the status bar itself changes… it's like is 80%grey and 20%red on 60Hz; 90%grey and 10%red on 90Hz, 50%grey and 50% red on 120Hz (it's like the status bar is dark-brown coloured).
And, then again, increase slowly the brightness: the status bar will be "magically" turn back to its natural color, dark grey.
This is a big issue for a smartphone which costs about 960American dollars here in Italy! I'm thinking about to return it...
Click to expand...
Click to collapse

NajimKiSaad said:
madsud said:
If you wanna see the issue:
1) go to a dark room or in a room with almost no light.
2) add "Screen Frequency" toggle in the status bar, and lower the status bar to show the toggles;
3) lower the brightness above 40-50%;
4) use the toggle to swap frequency from 60Hz, 90Hz and 120Hz.
You will notice the colour of the status bar itself changes… it's like is 80%grey and 20%red on 60Hz; 90%grey and 10%red on 90Hz, 50%grey and 50% red on 120Hz (it's like the status bar is dark-brown coloured).
And, then again, increase slowly the brightness: the status bar will be "magically" turn back to its natural color, dark grey.
This is a big issue for a smartphone which costs about 960American dollars here in Italy! I'm thinking about to return it...
Click to expand...
Click to collapse
This means international version suffers with the same issue. What they have done to achieve such high refresh rates and such low response times must be the issue. Now if someone from asus can confirm if this tinting can be fixed via software update or not that will be the main factor for either keeping or returning the phone. The issue is already raised in zentalk forum and i have also commented there and the mod also has accepted the issue in his demo unit.
https://zentalk.asus.com/en/discussion/11085/display-red-tint-issue-on-my-rog-2
Click to expand...
Click to collapse

It's so minor I've literally never noticed it (until using your test image just now) and I've been using this phone for almost a month now. I'm filing this under not an issue for me.

Not an issue for me. My brightness is pretty much always set to 50% and 90hz - never even noticed it. If you're running brightness down around 20% then you're either pretending to be on an Ethiopian diet, or you have an issue with over sensitivity of your retinas and should get it checked out asap

bluegizmo83 said:
It's so minor I've literally never noticed it (until using your test image just now) and I've been using this phone for almost a month now. I'm filing this under not an issue for me.
Click to expand...
Click to collapse
This only affect night time usage with lights out or in low lit environments where you will keep your screen brightness low. Daytime usage is perfectly fine as 50% slider is not actually 50% screen brightness. So slider % remains high during day.
cheetah2k said:
Not an issue for me. My brightness is pretty much always set to 50% and 90hz - never even noticed it. If you're running brightness down around 20% then you're either pretending to be on an Ethiopian diet, or you have an issue with over sensitivity of your retinas and should get it checked out asap
Click to expand...
Click to collapse
Its clearly mentioned that its a non issue with brightness slider in range 50% and above. So you wouldn't notice it.
And by the way if you are using that high of brightness in low lit or lights out environment then maybe you have less sensitive retina and maybe get it checked.
This will only affect people who use this for night time reading and naturally dim the screen to read comfortably. If people use normal day brightness at night this will be a non issue for them.
The main point is is this a hardware or a software issue. And i have already hypothesized why this might be happening. You can read the posts above.

sanurocks said:
This only affect night time usage with lights out or in low lit environments where you will keep your screen brightness low. Daytime usage is perfectly fine as 50% slider is not actually 50% screen brightness. So slider % remains high during day.
Its clearly mentioned that its a non issue with brightness slider in range 50% and above. So you wouldn't notice it.
And by the way if you are using that high of brightness in low lit or lights out environment then maybe you have less sensitive retina and maybe get it checked.
This will only affect people who use this for night time reading and naturally dim the screen to read comfortably. If people use normal day brightness at night this will be a non issue for them.
The main point is is this a hardware or a software issue. And i have already hypothesized why this might be happening. You can read the posts above.
Click to expand...
Click to collapse
I don't think I would ever find myself in a pitch black room with just my phone and no other background light of any sort. I'm not that kinda guy
If you head over to the Asus forum, this is not a new issue. Asus have declared the reddish tint is normal behaviour of the screen at high Hz, so its hardware, not software, and operating as it should. Every handset will be exactly the same. If it bothers you too much, then maybe look at the Nubia Red 3S or Xiaomi Blackshark 2 instead. For me, its a non issue as like you said, i never drop below 50% brightness, and my retinas are poor, so I would never see it.. :fingers-crossed:

I always thought that xda subscribers were above fanboy-ism...

cheetah2k said:
I don't think I would ever find myself in a pitch black room with just my phone and no other background light of any sort. I'm not that kinda guy
If you head over to the Asus forum, this is not a new issue. Asus have declared the reddish tint is normal behaviour of the screen at high Hz, so its hardware, not software, and operating as it should. Every handset will be exactly the same. If it bothers you too much, then maybe look at the Nubia Red 3S or Xiaomi Blackshark 2 instead. For me, its a non issue as like you said, i never drop below 50% brightness, and my retinas are poor, so I would never see it.. :fingers-crossed:
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Click to collapse
To each his own. :good:

Xebeck said:
I always thought that xda subscribers were above fanboy-ism...
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We are all fans of something! :laugh:
This is my first Asus phone, and I'm coming from a long line of samsungs (the latest being the Note10+) and for what I do with the ROG2, its performance creams anything Samsung has ever produced.. so, when a negligible issue like red tint (don't forget Samsung had blue, sony had red also in the past) I'm willing to forgive it because 99% of the time it doesnt affect me. If you call that fanboy-ism, then so be it..

Looks like, red tint in the display, issue is widespread in most of the ROG 2 phones .
Asus has confirmed the same, but refused to say, if it is a SW issue or HW issue.
ASUS India @asusindia
Replying to @justreach2ram
Hi there, our team has identified this issue and we have given high priority to solve it as soon as possible. Request you to cooperate for the same.
sanurocks said:
There is a noticeable red tint on dark grey color everywhere while the brightness slider is set in range of 0-50%. Effect is more pronounced while using 120hz refresh rate and less while using other modes. 50% and above and the tint just disappears.
Does anybody suffers with the same issue? This is indian variant of the phone.
Attached image can be used for testing.
Click to expand...
Click to collapse

Question Screen shows a greenish tint

Hello.
My Note 10 Pro screen has a greenish tint that can get quite annoying. It mostly shows on dark grey colors and on the top and botton of the screen, it's less strong on the center. I tried to correct it modifying the screen settings color correction (this much) but this only somewhat improved it but it didn't get rid of it.
With full brightness it's not that strong, if the image has greys you can tell it's a bit greenish but it's not very noticeable unless you put it side by side with another screen.
I tried to take a photo but it's hard to tell the difference:
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
On low brightness it's very noticeable if the image has grey colors and you are using the 120Hz mode which makes it notably worse (60Hz mode still shows the green tint, but not was much).
(On this image I'm using minimun brightness)
Also if you use the 120Hz mode and you lower the brightness to minimun some wrong violet colors appear on the top and bottom of the screen, like the photos show:
These weird violet colors do not appear on 60Hz mode.
Is anyone else having this problem? I wonder if I got a bad OLED or instead just the Redmi Note 10 Pro's screen is not good overall. I could live with 60Hz mode but even then the colors still look a bit greenish and I didn't bought this phone for not using the 120Hz...
What do you think? Is it worth getting a replacement?

i think it is a hardware issue
it happened before with amoled screens
you should go to get a replacement

Most of the people are facing this tint issue in redmi note 10 pro. I have seen many people complaining that they are facing purple tint on 120hz mode. Well i haven't seen it by myself cause haven't received my phone yet. And now after hearing all this i am afraid what if my device start doing this tint thing. I hope xiaomi fix it asab with some updates

On my device when i overclock screen from 60 to 84hz green tint appear also. This is most likely hardware problem and not software. I was thinking to buy 10 pro :/

Stefke93 said:
On my device when i overclock screen from 60 to 84hz green tint appear also. This is most likely hardware problem and not software. I was thinking to buy 10 pro :/
Click to expand...
Click to collapse
What device do you have? Redmi note 10?

I have found that using the colors on "Automatic" instead of "Standard" helps with the greenish tint. I usually use standard because it's more faithful to the original colors and the automatic commonly gives a blueish tone (and it does here too) but this blue tone helps masking the greenish tint at 60Hz, so I find it better. On 120Hz it's not enough and it still looks too greenish at low brightness.

QuickFix_ninja said:
Most of the people are facing this tint issue in redmi note 10 pro. I have seen many people complaining that they are facing purple tint on 120hz mode. Well i haven't seen it by myself cause haven't received my phone yet. And now after hearing all this i am afraid what if my device start doing this tint thing. I hope xiaomi fix it asab with some updates
Click to expand...
Click to collapse
Same here with the purple tint. It's not a deal breaker though, once you know it and... don't watch movies in the dark (which is bad for your eyes anyway)... What might be one if you're after the 120Hz screen is that I think it doesn't adapt to the context as expected (120Hz in Miui even when nothing updates on screen, 60Hz in some fast games... Would have expected the opposite).
Still an awesome phone for that price. Didn't miss my Mix 3 anymore! (BTW I'll "sell" that one, if someone is interested - along with it's new screen that doesn't go on, motherboard is OK, selling it as-is, i.e. open and waiting for a repair. More details soon on Mix 3 forum).

TotallyNotAPigeon said:
I have found that using the colors on "Automatic" instead of "Standard" helps with the greenish tint. I usually use standard because it's more faithful to the original colors and the automatic commonly gives a blueish tone (and it does here too) but this blue tone helps masking the greenish tint at 60Hz, so I find it better. On 120Hz it's not enough and it still looks too greenish at low brightness.
Click to expand...
Click to collapse
I do have this issue btw did you get it replaced?

thank god my 10 pro seems to be fine... no green or purple tint or any other issues

Those photos are quite informative. However, we have been here many times with (am)oled devices. Unlike IPS, amoled are very susceptible to slight alteration of electricity that powers it. The less it gets, the more likely colour deviations are to occur. The solution is most likely to stay on standard settings until Xiaomi figures out or "refines" what's best configuration for every each screen it installed using update. Keeping the device in mid to high brightness usually helps since it pumps up higher electricity, thus more accurate the colours would show.

[email protected] said:
I do have this issue btw did you get it replaced?
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Click to collapse
I didn't, I didn't want to go through the hassle of getting a replacement, less when I could get another one with the same problem and anyway the problem only shows on 120Hz at low brightness so it's not like the phone is unusable... What I do is enable 120Hz on the morning and disable it at night which is when I use low brightness, it's a bit annoying but it's working for me until now, and tbh some days I forget about enabling it and I go through the day without noticing I'm using 60Hz. The rest of the phone works fine so whatever, I still consider it good for the money.
I said on my first post that I noticed the green tint even on 60Hz but I have been comparing it with other amoled smartphones without being able to notice a difference so I think this is just how this screen technology works and I was just too used to my previous LCD IPS colors. After using my phone for some days I got used to it and don't notice it anymore except when I use 120Hz and low brightness. I also switched back to Standard colors since Automatic was just too unrealistic.

I'm facing the same issue
I have a greenish tint,
I have DOT OS installed so, I will have to revert to MIUI and stock recovery right?
Do I have to lock the bootlaoder too? cause I heard unlocking bootloader doesn't voids warranty. How can I revert back any help?

General ROM work: Synchronous PWM frequency == Refresh Rate (120 Hz) to reduce motion blur for games

Hi everyone, first post. I've got a fun project for a custom ROM that gamers will love. I wonder if anyone else has tried it, or even if such a ROM / kernel already exists, but I know it's possible.
I signed up here cause I just ordered a Poco F5 Pro and want to either find or modify a kernel to install on it.
The purpose of this custom ROM would be to set the PWM frequency of the phone's OLED display to 120 Hz, and be equal to the refresh rate, but only for the 120 Hz mode.
I only intend to use 120 Hz mode whilst gaming (typically) but when doing so, since the phone doesn't support VRR (variable refresh rates) anyway, I see no reason not to use the brightness slider to reduce the motion blur.
As many here probably know, the PWM frequency is by default 1920 Hz on this phone, which is very high and was selected obviously to avoid headaches or eye-strain which is a common complaint with PWM dimming.
But in my case, while gaming, I would rather set the PWM frequency to be 120 Hz, so that when I modify the brightness, it trades off brightness for less motion blur.
If your PWM frequency isn't equal to the display Hz, you'll see duplicated images and it's not ideal from a smoothness perspective.
You need to sync the PWM frequency to the refresh rate if you want the duty cycle will modulate the brightness vs blur tradeoff.
On one extreme: 100% brightness = 100% duty cycle = full persistence = 1/120 Hz = 8.33ms.
On the other extreme: 10% brightness = 10% duty cycle = 10% persistence = 8.33ms * 0.1 = 0.833ms
8.33ms of persistence isn't great, 1-2ms would be better. Or anything in between. To do this effectively without requiring the final brightness to be too dim, one would preferably want to force the OLED peak brightness to be higher to compensate for the PWM dimming.
So I guess what I'd like to do here, and I'll share the ROM afterwards (unless one exists already that achieves this), is two things:
1) Change the display's PWM frequency from 1920 to 120 Hz,
2) Boost the peak brightness (DC voltage) of the display as high as possible, or proportionally, to compensate for reducing the brightness via the normal display settings.
I tried to do this years ago on a OnePlus 8 Pro, and I had the Linux kernel all downloaded (though some files were missing), but I ended up returning the phone and didn't want to void the warranty on such an expensive phone. Now on the POCO F5 Pro, the price is reasonable for me to take the risk, so I would like to try.
I know the Sony Xperia 1 iii / iv / v have such a feature, namely the "240 Hz motion blur reduction mode", which is just a fancy way of saying 50% duty cycle at 120 Hz with the PWM frequency set to be equal to the current refresh rate of 120 Hz. If you want 480 Hz or 960 Hz "motion rate" on that phone, all you need to do is reduce the brightness further, to 1/4 or 1/8th of maximum.
I'd like to do the same thing here, and I'm fairly sure other users would be interested in a custom phone ROMs for gaming or movie watching to reduce motion blur.
Thanks for listening! I could use a bit of help finding where the original source code for the Android kernel for these phones is, or if it's even possible. I presume so, if others are modding ROMs for other uses (like DC dimming, etc)
EDIT: I found this repo for Xiaomi phones, but sadly it doesn't have anything for POCO F5 Pro
GitHub - MiCode/Xiaomi_Kernel_OpenSource: Xiaomi Mobile Phone Kernel OpenSource
Xiaomi Mobile Phone Kernel OpenSource. Contribute to MiCode/Xiaomi_Kernel_OpenSource development by creating an account on GitHub.
github.com

DimTester77 said:
Hi everyone, first post. I've got a fun project for a custom ROM that gamers will love. I wonder if anyone else has tried it, or even if such a ROM / kernel already exists, but I know it's possible.
I signed up here cause I just ordered a Poco F5 Pro and want to either find or modify a kernel to install on it.
The purpose of this custom ROM would be to set the PWM frequency of the phone's OLED display to 120 Hz, and be equal to the refresh rate, but only for the 120 Hz mode.
I only intend to use 120 Hz mode whilst gaming (typically) but when doing so, since the phone doesn't support VRR (variable refresh rates) anyway, I see no reason not to use the brightness slider to reduce the motion blur.
As many here probably know, the PWM frequency is by default 1920 Hz on this phone, which is very high and was selected obviously to avoid headaches or eye-strain which is a common complaint with PWM dimming.
But in my case, while gaming, I would rather set the PWM frequency to be 120 Hz, so that when I modify the brightness, it trades off brightness for less motion blur.
If your PWM frequency isn't equal to the display Hz, you'll see duplicated images and it's not ideal from a smoothness perspective.
You need to sync the PWM frequency to the refresh rate if you want the duty cycle will modulate the brightness vs blur tradeoff.
On one extreme: 100% brightness = 100% duty cycle = full persistence = 1/120 Hz = 8.33ms.
On the other extreme: 10% brightness = 10% duty cycle = 10% persistence = 8.33ms * 0.1 = 0.833ms
8.33ms of persistence isn't great, 1-2ms would be better. Or anything in between. To do this effectively without requiring the final brightness to be too dim, one would preferably want to force the OLED peak brightness to be higher to compensate for the PWM dimming.
So I guess what I'd like to do here, and I'll share the ROM afterwards (unless one exists already that achieves this), is two things:
1) Change the display's PWM frequency from 1920 to 120 Hz,
2) Boost the peak brightness (DC voltage) of the display as high as possible, or proportionally, to compensate for reducing the brightness via the normal display settings.
I tried to do this years ago on a OnePlus 8 Pro, and I had the Linux kernel all downloaded (though some files were missing), but I ended up returning the phone and didn't want to void the warranty on such an expensive phone. Now on the POCO F5 Pro, the price is reasonable for me to take the risk, so I would like to try.
I know the Sony Xperia 1 iii / iv / v have such a feature, namely the "240 Hz motion blur reduction mode", which is just a fancy way of saying 50% duty cycle at 120 Hz with the PWM frequency set to be equal to the current refresh rate of 120 Hz. If you want 480 Hz or 960 Hz "motion rate" on that phone, all you need to do is reduce the brightness further, to 1/4 or 1/8th of maximum.
I'd like to do the same thing here, and I'm fairly sure other users would be interested in a custom phone ROMs for gaming or movie watching to reduce motion blur.
Thanks for listening! I could use a bit of help finding where the original source code for the Android kernel for these phones is, or if it's even possible. I presume so, if others are modding ROMs for other uses (like DC dimming, etc)
EDIT: I found this repo for Xiaomi phones, but sadly it doesn't have anything for POCO F5 Pro
GitHub - MiCode/Xiaomi_Kernel_OpenSource: Xiaomi Mobile Phone Kernel OpenSource
Xiaomi Mobile Phone Kernel OpenSource. Contribute to MiCode/Xiaomi_Kernel_OpenSource development by creating an account on GitHub.
github.com
Click to expand...
Click to collapse
https://github.com/MiCode/Xiaomi_Kernel_OpenSource/tree/mondrian-s-oss <-- this is the source

Thanks!
I read somewhere that K60 and F5 Pro share the same code, but want to make 100% sure if I compile this and install it, I won't bricky my brand new phone.

TeamMex said:
https://github.com/MiCode/Xiaomi_Kernel_OpenSource/tree/mondrian-s-oss <-- this is the source
Click to expand...
Click to collapse
Hi klozz, are you bringing los to mondrian?

keaheng said:
Hi klozz, are you bringing los to mondrian?
Click to expand...
Click to collapse
I'll give it a try when I have some free time

Minor update: I wasn't sure if this project was even necessary, after I discovered the VR Settings option in the Display Settings on the Poco F5 Pro (and presumably many other HMDs), but it doesn't seem to do anything or actually work, sadly.
I'm not just doing this for VR use, of course, but I want to be able to lower persistence for gaming in general, however watching HDR at 120 Hz in VR on this phone was and is my primary objective. I will mod the kernel if I have to, but I haven't written off trying to get Google VR Services / SetVrModeEnabled API working yet. It currently doesn't work, inside the Cardboard SDK's "Hello Cardboard" sample Android project, but neither does my Galaxy S7 and that should work, or at least it used to.
You can set the brightness of the display in code, so presumably if you can force VR low persistence mode to be enabled on this phone, you can lower the brightness to reduce the persistence (which is how PWM dimming works, it trades off brightness for lower blur in equal measure, you lower one and the other raises and vice versa).
Unless someone knows of a way, or an app, or another ROM, to force Game Mode to activate "Vr mode" or low motion blur modes. I'm not in a super rush to get this working, it's more of a hobby project, but I would appreciate any tips / insights / feedback. Especially where to dig into the kernel source to change the PWM frequency from 1920 to 120 Hz, even if it's hardcoded for now, I could use a hack like if you lower the brightness below 25% it switches the PWM frequency to 120 Hz. That would let me install the ROM and not worry about toggling it on or off. Or if there's an ADB command like there used to be on Samsung phones to toggle low-persistence mode on/off on GearVR-enabled Galaxy phones.

I spoke with several VR experts and it seems like most mobile phones have discontinued support for "VR mode" aka low persistence aka setting the display's PWM dimming frequency = refresh rate.
I am forced to investigate this further, but before I even try to boot a custom ROM on this Poco 5 Pro, let alone compile one myself, I will attempt to find the exact place in the kernel that configures the brightness of the OLED panel (the duty cycle), and see whether the interface permits one to specify some arbitrary PWM frequency, as well as the duty cycle. If there is no such API or parameter, then this project is DOA as it would be something baked into the firmware of the driver board (1920 Hz frequency). If I can even find "1920" as a hardcoded constant somewhere in the kernel, then that's a positive sign. If not, I may have to abandon this and use something like LCD shutter glasses for 3D projectors to achieve low persistence. But that's not great as it cuts light significantly (50% or more due to the polarizing layer).
I guess I'm writing this to ask people here who probably know way more about Android kernel hacking than I do, whether this is indeed possible (configuring the PWM frequency in code).
If it does work, I'll of course publish the ROM and potentially even make it a simple ADB command so you can enable it in any game (this would benefit 2D games as well, to reduce motion blur at the expense of peak brightness. but many people already use sub 100% brightness so that sacrifice may as well go towards lowering the motion blur. this doesn't happen with a PWM frequency of 1920 Hz, naturally).