yashsingh1/xdaforums huggingface dataset:
[Galaxy Note 4 General] noterio:
Maybe I need to buy one or go to a store to see for myself.

I tried measuring a tablet I have, and at 1/60 shutter speed I count 10 lines. That means it's cycling on and off at 600Hz, or 600 times per second. That doesn't seem right, because that sounds very high, and there's no way I could see it. But on that tablet I cannot lower the brightness below 100% or I see strobing that feels disorienting and hurts to look at.

I also see it on my desktop monitor if I lower the brightness below 100%, a laptop, an OLED music player, and other LED things around the house.

My Galaxy Note 1 doesn't do that. If it's flickering, I don't notice. But the Galaxy Note 4 is measured to turn on for a short burst 240 times per second. If 600 is difficult to look at, then wouldn't 240 be worse?

Here's some quotes I found on the web:

"I purchased Galaxy SIII some time ago and the eye strain and headache were intense after use for some time."

"The (Note 3) screen appears to be flickering, more under certain brightness settings, as though some cheap low frequency PWM is used to control the brightness."

Is there anyone out there who can see it on the Note 4? Like if you lower the brightness to minimum, and look at text on a white page, then look away real fast, do you see sharp strobe trails as your eye looks away?
[Galaxy Note 4 General] sonyfan12:
amoled without flickering (PWM frequency is increased)

lg g flex, fly iq444, motorola razr hd, moto x 2014, perhaps nexus 6

http://www.youtube.com/watch?feature=player_detailpage&v=wwkphpnl44s#t=821

http://www.youtube.com/watch?v=EynkwkrhDyQ

http://www.youtube.com/watch?v=pwVAr_lOAmk&feature=player_detailpage#t=289

http://www.youtube.com/watch?feature=player_detailpage&v=ooTfiijV8gk#t=436

http://www.youtube.com/watch?v=nmYP3KNbG3k&feature=player_detailpage#t=524

http://www.youtube.com/watch?feature=player_detailpage&v=PL_HH1mjwb0#t=227

http://www.youtube.com/watch?feature=player_detailpage&v=6lyOIMH9LEY#t=1133

http://www.ixbt.com/mobile/motorola-xt925.shtml

http://www.ixbt.com/mobile/lg-g-flex.shtml

http://www.ixbt.com/mobile/fly-iq444.shtml
[Galaxy Note 4 General] usmaak:
I've had the SGSIII for almost 2.5 years now, and this is the first that I've heard of this. Maybe I'm not sensitive to it? That would be weird, because I used to have to buy special monitors with a higher refresh rate to avoid headaches.

I've looked at several Note 4 in Best Buy, and haven't noticed it at all. But I admit that the chances of noticing it in the glaring lights of a Best Buy are pretty poor.

I'll get one. If I start having headaches or other symptoms, I'll return it and get something else. Love that 45 day return window at BB.
[Galaxy Note 4 General] i_guana:
I have a 1000fps camera and I think I will put this issue to the test and put it to rest. I have a Note 3 so that's all I can test. I'll report back as soon as I can.
[Galaxy Note 4 General] sonyfan12:
more amoled smartphones without flickering

http://www.youtube.com/watch?feature=player_detailpage&v=DxdvudupsHk#t=688

and perhaps this

http://www.youtube.com/watch?v=u3L-bHADOVM

need to watch the video with the dim lighting and the display shows white color﻿
[Galaxy Note 4 General] Magnesus:
I have the phone now and have tested it and there isn't any flicker visible even when you put it on the border of your view at any brightness setting (be it low or high) and any ambient light (even at none).

Videos will always show flicker because of how cameras work.
[Galaxy Note 4 General] jajo83:
Got my Note 4 yesterday and the flickering makes me crazy. Previously had SGS4, Note 3, LG G3 and none of them have this problem. Also checked a SGS5 and it does not flicker. I can see the flickering at any brightness setting, even the highest one.

So whatever they did, it is not a general AMOLED problem. It is a problem with my unit, or a Note 4 problem.

/ Jacob
[Galaxy Note 4 General] sonyfan12:
http://xdaforums.com/showpost.php?p=56218569&postcount=25

---------- Post added at 03:19 PM ---------- Previous post was at 03:18 PM ----------

Are you troll?
[Galaxy Note 4 General] jajo83:
No, I just wanted to share my opinions since this is clearly a problem on my unit. Maybe it is just a faulty unit, but there are several threads about flickering on the Note 4 so I guess not. The PWM frequency is probably lower than on Note 3, SGS 4/5. Most people are less sensitive to flicker than I am and would not see it. Out of ten people in my office, three can see it clearly.

/ j
[Galaxy Note 4 General] noterio:
It might not be a problem with yours. Can you go to a store to see if the others are like that?

Eyes can see flicker higher than 240Hz. Not everyone senses it the same, but if you did an experiment to compare a screen with and without PWM backlight, many people would correctly identify which one has the PWM with their eyes alone.

If you set it to full brightness, it shouldn't be as noticeable. But if you set it to the lowest brightness, then many people should be able to see the Galaxy Note 4 screen flicker.
[Galaxy Note 4 General] sonyfan12:
UPD. nexus 6 have flickering

http://www.youtube.com/watch?v=_OdDDXUg-mA

list of amoled smartphones without flickering

lg g flex, fly iq444, motorola razr hd, moto x 2014, Gionee Elife S5.5 and perhaps oppo r5
[Galaxy Note 4 General] sonyfan12:
motorola droid turbo no flickering!

http://www.youtube.com/watch?v=H99hZI70WGE
[Galaxy Note 4 General] eddhard:
Why don't people every remember that every screen is different. I don't care what brand, device or model you have. Even computer screens of top of the line TV 's. I got lucky. I have a great screen. I have even use a spectro to measure the calibration and it's pretty good. Not ISO standard but the closest I have owned. If you are not happy with your screen then exchange your hand set. None of us have had them long enough not to be able to exchange them.
[Galaxy Note 4 General] noterio:
Every single Galaxy Note 4 uses pulse-width modulation so will have a flickering effect. Exchanging it is useless.
[Galaxy Note 4 General] foo:
I don't experience any flickering on the Note 4 nor on my Galaxy S3. This is the first time I'm hearing about this.

Forget about any video you see about it, because of interference with the camera shutter speed.
[Galaxy Note 4 General] sonyfan12:
http://www.ixbt.com/mobile/samsung-galaxy-note4.shtml

http://www.youtube.com/watch?v=3tmSMQA_k8U

---------- Post added at 07:46 AM ---------- Previous post was at 07:41 AM ----------

new video with nexus 6

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

to see flickering in video need to find the video with the dim lighting and the display shows white color﻿ on medium brightness or any color at a low brightness

https://www.youtube.com/watch?v=F1l...EHSy4sNS1txEQ&feature=player_detailpage#t=172
[Galaxy Note 4 General] eddhard:
Post all the evidence you want. I am aware that all screens have it to some degree. But reading this thread and many others it's clear that some screens are worse than others. At this stage in ownership you can exchange or return your phone for any reason. You normally have 20 -30 days grace under consumer legislation.
[Galaxy Note 4 General] noterio:
We don't know if some screens are worse than others, because nobody is doing any scientific testing. People could be perceiving the same exact screens differently. If one person who sees flickering records a video, and so does someone who says their screen doesn't flicker, then we could at least see if we notice anything obviously different with their screens when recorded by a camera.

Or the people who see something could describe it better. There's also an unrelated issue with some AMOLED screens that have been recorded on video where it's randomly flashing, which also happens when the battery is about to die. If someone sees flickering that is random, that is not PWM. Pulse-width modulation will be exactly repetitive like a strobe light, and it will be more obvious at minimum brightness.
[Galaxy Note 4 General] Magnesus:
Don't worry about it. It's not posibble to see it, people are just paranoid. Video will always show flickering because of how recording works, just ignore it. Your eyes are not a video camera. ;)
[Galaxy Note 4 General] sonyfan12:
http://www.youtube.com/watch?v=3tmSMQA_k8U

http://www.ixbt.com/mobile/samsung-galaxy-note4.shtml

http://www.tftcentral.co.uk/articles/pulse_width_modulation.htm

http://www.flatpanelshd.com/focus.php?subaction=showfull&id=1362457985

I will not rest until you calm down
[Galaxy Note 4 General] noterio:
To anyone saying it's impossible to see the screen flicker, if I can see it with my eyes will you pay me the $750? Why write things when you don't know what you're talking about? It's like if I insist that nobody could jump high enough to dunk a basketball. Maybe you can't, but plenty of people can.
[Galaxy Note 4 General] homer285:
Um I dont think plenty of people see anything you're talking about, however, you have made your point and you have said LCD is better, so why preech on and on? Sell your flickery device and buy a non flickery device, simple!
[Galaxy Note 4 General] noterio:
I have the Galaxy Note 1 and it doesn't flicker. I was going to buy the 4, but wanted info about its PWM. But instead of testing and posting videos they post opinions, which conflict because one says they don't notice anything, and another says they do. How is that useful? There are hundreds of Galaxy Note 4 videos now, and I've not seen a single one where they move the brightness slider very slowly to show how bright it has to be to minimize flickering. Nobody talks about this, so we need to raise awareness. Otherwise Samsung will never find a way to make flicker-free AMOLED in new devices.
[Galaxy Note 4 General] jesstech:
Unfortunately I can also see my Note 4's PWM at work. It is most visible in the dark, and it often plays havoc with the framerate of movies. To those of you saying this is an aberration that can only be seen in videos, you should consider that this also applies in reverse—to videos displayed on the screen. As a test, play a feature film and skip to the end. Watch the white credit text scroll on a black background and see if you notice it. Then flip your phone around, point it at a surface, and watch what happens with the ambient light. It's noticeable. If your eyes are sensitive enough you will be painfully aware of this any time the camera slowly pans across a scene.

At 240hz the flickering rate may seem to you to be "too fast to see" but the bigger problem at hand is not the speed, it's the magnitude. This screen drops the brightness in every cycle significantly enough to be noticed. The fact that this is visible even at 100% brightness (where PWM shouldn't be used at all) speaks to an engineering oversight. My hope is that this is something that can be tempered by a software update or tweak. Even still, I'm genuinely considering returning my Note 4 because of it. What's the point of this gorgeous display if it makes watching media on it sickening?
[Galaxy Note 4 General] jajo83:
It is also clearly visible on interface animations, like fade in or out effects.

On my unit the brightness level has nothing to do with the amount of flickering. I can see it on the lowest setting but also on 100% brightness. However, there has been moments when I haven't seen any flickering at all. I think this is strange. If it is a PWM issue, the flickering should be visible all the time, right?

I am considering exchanging my unit to see if it is just an issue with this one.

/ j
[Galaxy Note 4 General] razno:
On s5 i now and then id sense flickering... That said, I never thought about it until I read about it here.

Here are 3 pictures of mine S5 at 100, 50 and 25 brightness.

Pictured with dslr at 1/4000 shutter.
[Galaxy Note 4 General] AndreiLux:
That's amazing.

This is not PWM at all if these pictures are correct. This is scanning of a black stripe much like CRTs back in the day but to decrease perceived brightness.
[Galaxy Note 4 General] razno:
It's pwm, refreshing - not all at once but from top to down in stripes probably because it better for perception. If I shoot portrait mode because cmos refreshing I catch motion...
[Galaxy Note 4 General] AndreiLux:
Well yes technically it's pwm, but not due to the pixels themselves. Your pictures point out that the luminosity of the pixels never changes, meaning this is their brightness control mechanism.
[Galaxy Note 4 General] razno:
But they flicker ;)

In lowest brightness there is only stripes few mm wide lit.... About 5 at same time rolling....
[Galaxy Note 4 General] noterio:
[YOUTUBE]aPYBFZV8Jqs[/YOUTUBE]

That's how PWM looks in a camera, with rolling lines.
[Galaxy Note 4 General] razno:
Yep. It's not as bad as ful on off states, but luckily s5 do it an high frequency...

On monitor i get around that with 100% brightness on monitor and than lower it in settings....
[Galaxy Note 4 General] sonyfan12:
more amoled display without flickering

http://www.ixbt.com/mobile/lg-g-watch-r.shtml
[Galaxy Note 4 General] razno:
After selling s5 and using a s2 as stopgap and using my new note 4, I found this pwm like" strain my eyes. Using if in low brightness for some time and I feel a little unpleasant and see flicker. Moving my eyes from point to point is somehow harder.

So I get s 2 again and it's better to use. So I get my Nikon dslr and it confirmed problem - s2 don't use pwm like rolling brightness control.
[Galaxy Note 4 General] Jonathan-H:
Seriously ? Do you people sit around trying to make this stuff up?

I give up with xda. My screen does not flicker and i have excellent vision.

Sure if i record my screen with a camera i might see refresh of some sort but who cares.

Get out and enjoy the world. Better still. . Find a better phone screen. . Oh wait.. there isnt oje.
[Galaxy Note 4 General] razno:
Your problem is in your ignorance.

You don't see it, or doesn't bother you. But that does not mean no one doesn't see it.

You see, i have sensitive vision. Not perfect or better, just sensitive. I see 1 fps drop in games vsync outside 60 because its not smooth and its unrealistic in my eyes. I also had tears in eyes back in pc crt days when i had to work half an hour on computer on 60 hz if it was impossible to bring up at least at 75 hz.

I would be very happy if such things doesn't cause me eye strain and i don't notice. I notice pwm in lcd.

Have friend who don't see any difference between movie 30 and 60 fps.... and that one is not even suptle one.

Excellent vision has nothing to do with it.

Here is picture of s2 and note 4 at minimum brightness at 1/4000.
[Galaxy Note 4 General] bekasulaberidze:
I noticed display flickering on full brightness on light backgrounds, so this is not a manufacturer defect and it is ok to flicker on galaxy note 4 ?? should I bring to service Centre or not ?
[Galaxy Note 4 General] mkim055:
[MENTION=4641142]razno[/MENTION], holy **** you notice 1fps drop... I feel sorry for you...

How do you play games or watch anything when fps is always fluctuating.

If you can notice 1fps change, prob best to go see a doctor.....gg

Not a sarcasm btw.

Sent from my SM-N910U
[Galaxy Note 4 General] rj3005:
Another whiner thread...

If you don't like samsung's chosen pwm frequently buy another phone.
[Galaxy Note 4 General] razno:
It's not problem in one fps, problem is that it's out of sync so you have stutter as one frame is displayed as two and then next one are 2 frames away.

Vsync magic. Without it game is not smooth either. 80 faps, but not buttery smooth.
[Galaxy Note 4 General] sefrcoko:
This thread isnt going anywhere anymore :). Most people have no isssue with Note 4 "flickering". Some apparently do. Samsung won't be fixing this because it's not a bug, it's simply built this way. Maybe some have a faulty unit or ultra-sensitive eyes. Andreilux already said too complicated to fix this at the kernel level, and if anyone knows it would be him! Not sure what more can be said!
[Galaxy Note 4 General] Osmic:
PWM is a real problem

I can confirm that I also have eyes very sensitive to PWM. I just bought the LG ec930v OLED TV and it is unusable for me. My eyes start to hurt and get wet in 20 minutes after watching. I can confirm the flicker with my DSLR.

I also have a HP27 inch computer screen and that does not flicker at all with any setting of my DSLR and it has also been confirmed by TFT central and some other review sites that it does not flicker. I can use the screen for any amount of time without any fatigue or eye strain. But any display that has PWM, causes immediate eye strain. A problem that I have confirme over and over with several devices. E.g. Surface Pro 2 flickers when the brightness is not 100 %. I can use it with no problems when the brightness is 100 % but immediately when I turn the brightness to e.g. 95 %, I get eye strain. The strain is so bad that my eyes are red and sore the whole next day, if I've used a display with PWM.

Galaxy S2 does not flicker and I had to use that for years, as GS3 and GS4 both flickered. Then I got Sony Z2 which does not flicker. At work I have displays that flicker if the backlight is not 100 %, so when ever I go to a workstation and forget to turn the display brightness to 100%, I find my self wondering, why my eyes get wet and irritated, while I realize I forgot to turn the backlight to 100.

I do not claim that I see the flicker, I just sense the side effects of it.

I'm writing this because this is an important issue, I find it very difficult to find a phone, TV, Computer etc. as I always need to test it out with a DSLR to be sure that it does not flicker. I was not able to properly test the LG, so now my eyes are red and burning and I have to take it back or sell it.

This is absolutely no hypochondriac or any other bs like that. This is a real issue that some people suffer and manufactures should be pressed to stop using PWM, as I do not believe it is completely harmless even to those who do not get obvious eye strain.

A bit like Celiac disease, some can eat bread without problems, some can't. It is not helpful to state "Well, I ate a whole loaf of bread last night an got no problems, you are just a hypochondriac to claim that you can't eat bread"

If you do not understand this, skip this topic but do not try to ridicule those who have this problem. It is real.
[Galaxy Note 4 General] sefrcoko:
Definitely not ridiculing anyone here, just not sure what anyone in your position can actually do about it (other than researching this before you buy a particular phone).
[Galaxy Note 4 General] Osmic:
Great. Yes, I agree, there is little that can be done about this. I went to a Consumer electronics store and "measured" about 15 televisions with my DSLR and only one did not flicker. But that one was the Sony X95 which was rated 6/10 and deemed unsuitable for movie watching due to horrible black levels. So I ended up with the LG Oled tv in hopes that the flicker rate is high enough, as it was flickering the least of the TV's that flickered. If I take a picture of the TV with 1/4000 shutter speed, I see one black vertical line in the screen, which I interpreted that the PWM frequency is then 4000 Hz.

Samsung LCD's and Galaxy phones have a PWM of 240 Hz, which makes my eyes burn in 15 minutes, badly.

I've noticed that there are a lot of commercials for lubricating eye drops. I also see people applying eye drops unusually often. Could it be, that the sudden increase of eye problems in the general population is also due to the PWM flicker, but most people do not have it so as bad, so they can just apply eye drops every now and then, when they have been staring and a PWM screen for many hours during many days.

If the awareness about this problem would be increased, then there would be a chance that a some point the manufacturers would stop using PWM. Some PC display manufacturers like Eizo, Benq and HP have already caught up with this.
[Galaxy Note 4 General] rj3005:
I call it BS, Why? Because if you have problems with 240Hz flickering mobile phones would be the least of your problems... every light (especially any kind of fluoricent )in your house, at work , shopping mall flickers at 50 or 60 hz (depending on the country you live ) movies in cinemas play 24 frames a second with double shutter making them flicker at 48Hz
[Galaxy Note 4 General] xxaaronxx:
It's not bull****. The flicker is the first thing I noticed with my Note 4, and it's much more apparent in peripheral vision.

I don't really see flicker in fluro tubes, I do in CRT displays, and I haven't been to the movies in a long time so I'm not sure about that.

But I'm really sick and tired of people saying it's bull**** and impossible to see. Some people say they have 20/20 vision. That's irrelevant, the visible flicker has more to do with the brain, not the eyes, and having less than 20/20 vision wouldn't inhibit the ability to see flicker...

The people who keep calling bull**** are hindering this problem being fixed. It's very real, if you can't see it you're lucky. To the people calling it a "whine" thread, you really have no idea.

If you were capable of seeing the flicker you'd be in the same boat as me and many others, complaining on forums. It's the only way to get noticed and hope for a fix.
[Galaxy Note 4 General] bekasulaberidze:
I hate this phone, it is downgrade from note 3, awful battery life, screen flicker, what else ? drains very fast at normal usage -1% in 1 minute ? it is not normal !
[Galaxy Note 4 General] sonyfan12:
Lamps have a large inertia therefore the amplitude of the brightness drop there is small. In the movies and just in the video when switching frames brightness doesn't drop
[Galaxy Note 4 General] Osmic:
rj3005 I guess you are just a troll?

If you cannot understand something, please always remember, that it does not mean someone else could not understand it.

As other stated, the fluorescent lights do not dim so abruptly as leds, it is a curve/wave shape, instead of sharp flicker. Leds go dark in an instant without glow, that's why it irritates the eye, as it is a very unnatural change in brightness.

I have had zero problems with CRT tv's. The problems started with displays with higher refresh rate than 120 hz, but those were minor and only after hours of use. Now wi the LED lcd's the problems start in minutes.

And - how would you explain the red eyes if the backlight is not 100% but no red eyes if it is 100%? Are you saying that I'm able to "generate" red eyes as a hypochondriac reaction? Even in the case when I do not know the backlight is not 100% (has happened to me many times, that someone at work dims the brightness of a display I have been using and suddenly someone comments, if I have a hangover as my eyes are red. Sure enough, I check the backlight and it is not 100 %

But it is pointless to try to fight your level of ignorance. I assume you are one of those who claim that Celiac disease does not exist just because you can eat bread and because the people suffering Celiac can eat other grains, so why would e.g. wheat suddenly be a problem?

It's so strange that when ever this issue is discussed, there is always some brainiac who tries to dismiss it as bs, while even some of the manufacturers are already producing flicker free displays. Mind you, it is much more expensive to produce flicker free displays, so rest assured, the manufacturers would do this if they thought that this is a problem of a couple of hypochondriacs with oscillators to measure the flicker.
[Galaxy Note 4 General] Magnesus:
Both not true. Go to the optometrist and/or check for allergies because something is wrong with your eyes and it's not cause of PWM (most likely dry eye syndrome but it also could be an allergy). Also make sure you have brightness of the screen (and brightness in your room) at proper level - too high or too low might cause eye strain, the same as not blinking (make sure you blink often when using your device).

Also no need to be agitated, you can always use another device if you are convinced it's Note 4's fault.