It would be great if somebody can test it, thanks in advance.
How to test:
put a camera in front of the screen and play around with the shutter speed and the brightiness of the screen. When lines appears on the screen, its not good => pwm, without lines => good :good:
edit: i had links for pwm explanation, but not enough posts, sorry..
The question is about pulse width modulation, which I'm reading occurs when both of the following are true:
- you are using an LED light source with variable brightness
- you are using a camera with a rolling shutter
http://provideocoalition.com/aadams/story/pulse_width_modulation_is_not_your_friend/
The camera on the note 8 does not have an LED flash, so I think the poster either now knows that it won't be an issue, or is curious as to whether display brightness on the screen is controlled by pulse width modulation or a different technique.
In the latter case, I don't know, and since this is stuff that can't be seen by the eye nor in the viewfinder, but mostly in photo editing suites per the article I link to, I'm not sure why it's an issue here.
Hi roustabout
I think we dont speak about the same topic.
What I mean is the flickering of the display. A good example is found on youtube: Nexus 7: no PWM on LCD
A lot of LCD use this technology to dim, but its not proper dimming, just switch on / switch off the the lcd very quickly.
Some people have problem with this flickering but dont know that theres a problem, so for example dry eyes, getting tired very fast when working on the computer..
I think more the 95% of the usual monitors use this technique.
I hope this helps.
no, we're talking about the same thing:
'curious as to whether display brightness on the screen is controlled by pulse width modulation or a different technique.'
The article I found thinks it's not visible; what you've read or experienced suggests it's problematic.
What I can say is the first-gen ipad was very hard on my eyes; the note 8 is not like that, but not as good as e-ink. Much more fun than e-ink, though!
Related
I just got my Galaxy nexus (an hour ago), and I'm getting around using it pretty well except for one thing which is annoying me big time.
The screen seems to dim or change its color balance when viewing certain things. Whites are usually dimmed at most times, but when I view other things, the dimness goes away and whites become very radiant.
It seems like the phone is adjusting automatically to things on the screen for the sake of energy saving. How do i disable this!?
Yes, I have my Brightness on manual and set to full. That is not the issue.
okay wow this is getting annoying... Two more issues:
1-The thing won't transfer files while im using windows 7 "the device has either stopped responding or has been disconnected". When using OSX Lion, it isn't even detected.
2-There is chinese text here and there no matter what I do for language settings.
This is my first android phone ever, and I'm not liking the experience so far...
Look, I've tried searching for these two issues, and I did not find any threads with them resolved. Maybe I'm computer illiterate. Maybe I have a very low IQ, but can you just help me resolve these issues IF you know how to resolve them without just going into my thread and be like "Oh look, another noob", and proceed with leaving?
PS: I AM A NOOB.
Protip 1. Read up on amoled technology a little. And then read some of the issues some phones like galaxy s2 had. Your dimming is normal. It sounds like you're just more sensitive to it.
Protip 2. Download the appropriate drivers. In device manager, you want it to say android adb interface when you're phone is plugged in.
Protip 3. Take a chill pill. It is okay to be a noob. It happens. Your attitude comes off as annoying or you're freaking out over nothing. Solving problems take time and we are not sorry xda can solve them instantly for you. Patience, amigo.
My grandma beat me down and took my nexus. Sent from a jitterbug with beats by dre.
You might try turning of Auto Brightness and set it somewhere you feel comfortable... I just decided when I got this phone that I'd make myself get used to the adjustments and it's worked out well.
IMHO the adjustments going from white to black are less noticeable on 4.0.3
As far as the dimming, you have Auto Brightness on. Go to settings, screen and set the brightness to something else.
Sent from my Galaxy Nexus using xda premium
Is_907 said:
You might try turning of Auto Brightness and set it somewhere you feel comfortable... I just decided when I got this phone that I'd make myself get used to the adjustments and it's worked out well.
Click to expand...
Click to collapse
GinoSylum said:
As far as the dimming, you have Auto Brightness on. Go to settings, screen and set the brightness to something else.
Sent from my Galaxy Nexus using xda premium
Click to expand...
Click to collapse
I take it you missed the part where the op said his brightness is set on manual?
samsung drivers
for the drivers use this post
http://forum.xda-developers.com/showthread.php?p=20311264
PDAnet installs the drivers for you nice and easy, then you can remove from your phone and pc and the drivers will stay behind.
at this time there is no way to disable the screen dimming function. samsung's other phones have this feature as well, with an option to disable it in settings. its a power saving feature. for whatever reason google did not give any option to turn this on or off. so for now we have to wait if maybe a ROM can disable it.
For OSX you need to download Android file transfer for it to be seen.
Sent from my Galaxy Nexus using xda premium
Thank you everyone ...Sorry for the attitude earlier.
It seems like I got one of the GNexus phones which have a really good screen (The colors are just mind blowing), its only the dimming thing which is getting in the way. Also, I've tried to update to 4.0.3 and checked out the developer's section of the GNexus forum, but the steps are kind of overwhelming and I'm having my final exams at university right now, so I'll have to wait for a week to just sit back and read everything slowly and correctly.
One more thing, is there a download link to the official 4.0.3 mod ? It seems like everyone here prefers modded images one way or another.
lol. the dimming you are referring to is probably from current draw or a trait inherent to amoled. some people have mentioned they notice "dimming" like on white background browser and you pop up your keyboard. the white will get dimmer or yellower, or black more grayish. this is what you're talking about?
pukemon said:
lol. the dimming you are referring to is probably from current draw or a trait inherent to amoled. some people have mentioned they notice "dimming" like on white background browser and you pop up your keyboard. the white will get dimmer or yellower, or black more grayish. this is what you're talking about?
Click to expand...
Click to collapse
Its the opposite. When you draw the keyboard out, the whites get brighter and stronger. I don't have yellowing on my phone (thank god), but I do have dimming.
top make it simple:
The more the blacks = The brighter/stronger the whites.
Clearly a voltage issue for power consumption's sake. As the phone physically switches of diodes to achieve true blacks, more energy flows to lit diodes and they in turn become brighter.
Isn't there some sort of tweak deep enough to give full power to all diodes at all times regardless of what's on the screen (Full power even if the entire screen is white) ?
Firstly, welcome to Android. Once you get used to it you'll love it. I gave the same problem Windows 7 sometimes usually large video files and need to say that the adb drivers are not required to transfer files to the phone - I don't have them installed and I can still transfer data.
I have to say this is my first amoled device and I haven't noticed any dimming unless I have auto brightness on of course which I understand you don't.
Sent from my Galaxy Nexus using XDA App
BLL00 said:
Its the opposite. When you draw the keyboard out, the whites get brighter and stronger. I don't have yellowing on my phone (thank god), but I do have dimming.
top make it simple:
The more the blacks = The brighter/stronger the whites.
Clearly a voltage issue for power consumption's sake. As the phone physically switches of diodes to achieve true blacks, more energy flows to lit diodes and they in turn become brighter.
Isn't there some sort of tweak deep enough to give full power to all diodes at all times regardless of what's on the screen (Full power even if the entire screen is white) ?
Click to expand...
Click to collapse
ah yes. you're correct. i had it backwards.
I have the same issue with transferring large amounts of data using Windows 7. Looking for a fix too.
Investing the time to learn how to setup the SDK and using ADB will be well worth it.
BLL00 said:
Its the opposite. When you draw the keyboard out, the whites get brighter and stronger. I don't have yellowing on my phone (thank god), but I do have dimming.
top make it simple:
The more the blacks = The brighter/stronger the whites.
Clearly a voltage issue for power consumption's sake. As the phone physically switches of diodes to achieve true blacks, more energy flows to lit diodes and they in turn become brighter.
Isn't there some sort of tweak deep enough to give full power to all diodes at all times regardless of what's on the screen (Full power even if the entire screen is white) ?
Click to expand...
Click to collapse
Out of the three results I found searching for this topic, I'm glad I checked this thread.
The exact thing I was wondering was:
Is there any way to disable the screen from getting brighter when my keyboard comes up on the screen?
From reading your response, it seems that the screen getting brighter is a result of the design of the screen, suggesting that there is no way to stop it from happening. The only thing I've been able to do to make the screen remain at the brightness I set it is to change the theme of my keyboard to a brighter or lighter color based theme.
I'm using Swiftkey with the Neon keyboard, it looks great and I love it!
I had a Samsung Vibrant previously to the Galaxy Nexus, and there indeed was a "Power Saving Option" in the settings and if I remember correctly that stopped the screen from getting brighter with the keyboard on screen. Has any fix / ability to change this on a stock Galaxy Nexus running JB been found? It's just barely annoying enough for me to notice it, plus I'm a stickler for more battery life and I can feel my battery dying the brighter the screen gets. ( I know this last part may be a mental thing, but still. Haha. )
Hi, my english won't be very good because it's not my native langage.
I'm very sensitive to the flicker caused by PWM (Pulse Width modulation) wich is a technique used in the backlighting of a lot of LCD display to dim the brightness of the screen. I'm a "migraineur with aura" wich is a neurological disease, so like epileptic people my eyes and my brain are very sensitive to all sort of visual stress even the most subliminal one like PWM used at a high frequency. And I wanted to know if the note 10.1 (2014) use PWM to dim the screen at all level of brightness? I m' sure that it use it a least until 50 %, and that it is not PWMed at 100% brightness. Cause at 50% i'm sick litteraly within second, and at 100% i'm ok. But I have not tested all the level between 50 to 100 cause if it's flicker I can have quite a serious seazure, which would leave me ill for days, so it's quite hasardeous for my health. So what i'm doing is that i leave the system brightness to 100% wich of course is too bright, but I dim it with a soft (screen adjuster) that can dim the display without touching the backlight. But it's not a perfect solution cause the display is still using a lot of energy that way and there's a lot amount of blue wavelenght coming from it and i'm sensitive to blue wavelenght too. Basically as you can see, LED backligh is not a very good technology for epileptic people, eye-sensitive or migraineur. (I personally think it's not a healthy tec for anybody)
So, I just wanted to know if someone know if there's an "official" level where the note doesn't use PWM anymore to control the brightness of the screen, I mean below 100? Thanks in advance, and i'm sorry if my post can sound a bit confuse, it's not easy to try to ask and explain something in a langage that's note your native langage. Thanks in advance.
Hi all!
Does anybody know if HTC 10 uses PWM (Pulse-width modulation) for brightness control?
PWM is a cheap and easy technology to manage screen brightness. To adjust brightness PWM-controller rapidly (usually with speed of 230-240 Hz) turns backlight on and off, which in turn could cause headaches and eye fatigue after using the device.
More about PWM: https://en.wikipedia.org/wiki/Pulse-width_modulation
Absence of PWM is one of the key parameters for me. Unfortunately only a few reviewers test flickering and this information is very hard to find. So far, I have not found a single review with PWM test.
Thank you!
21.05.2016 update: Notebookcheck confirmed that HTC 10 is flicker free!
Surely the only way to dim LEDs is with PWM?
Nope, PWM is just the cheapest an the easiest way. Plus controller won't overheat.
But there are other ways to dim LEDs. One of the oldest ways - variable resistor.
Considering humans see appx 60-90 hz I'd say this is a non-concern.
Unless you're a mutant who can see 100hz+ in which case you must go crazy anywhere you go from the constant exposure to higher frequencies.
Sent from my HTC One using Tapatalk
Considering that I had 5 laser eye surgeries this concerns me a lot.
Using a screen with PWM for more that 15 minutes causes eye strain for me. And this is the main reason why I haven't already bought Galaxy S7.
You are lucky that PWM doesn't affect your eye, and probably should google further more: https://www.google.ru/?#safe=off&q=pwm+eye+strain
datafoo said:
Considering humans see appx 60-90 hz I'd say this is a non-concern.
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Click to collapse
Where did you get that info? Especially flickering can be seen at even higher frequencies. I personally see flickering on the XPS 15 and it uses PWM at around 362 Hz.
http://www.notebookcheck.net/Dell-XPS-15-2016-9550-InfinityEdge-Notebook-Review.156354.0.html
It's not disturbing but it is noticeable.
http://www.100fps.com/how_many_frames_can_humans_see.htm
Also the difference between 60 Hz and 144 Hz in a monitor is obvious just by dragging windows around.
If you can't see it, fine. But don't go around telling untrue stuff please.
Dr. lele said:
Where did you get that info? Especially flickering can be seen at even higher frequencies. I personally see flickering on the XPS 15 and it uses PWM at around 362 Hz.
http://www.notebookcheck.net/Dell-XPS-15-2016-9550-InfinityEdge-Notebook-Review.156354.0.html
It's not disturbing but it is noticeable.
http://www.100fps.com/how_many_frames_can_humans_see.htm
Also the difference between 60 Hz and 144 Hz in a monitor is obvious just by dragging windows around.
If you can't see it, fine. But don't go around telling untrue stuff please.
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Click to collapse
Untrue stuff LOLOLOLOLOL - I believe you're suffering a nocebo effect.
Pardon my incredulity but as I mentioned if you see anything over 100hz you're a mutant (I said 60-90hz) and that appears to be corroborated by your 100fps link. I'm not completely disagreeing with you, I'm however pointing out that you're such a small subset of the population it's rare and hard to validate.
Although FPS and HZ are different we'll bypass the semantics for the fact we're discussing cycles per second in a general fashion.
It must drive you crazy being ANYWHERE with lighting and electricity. At least here in the US electricity runs at appx 60hz so lights (most computer monitors etc) must bother you quite a bit.
Either way, good luck to you. I hope you find what you're looking for.
There is of course a difference between the way LCDs refresh their content and the way CRTs did. Strobing of light can definitely be seen at much higher rates than you said.
Also I never said that it's infuriating or drives me crazy I just said it's noticeable. I have no idea where you get this from.
Tests with Air force pilots have shown, that they could identify the plane on a flashed picture that was flashed only for 1/220th of a second.
That is identifying. So it's pretty safe to say, that recognizing, that SOME light was there is possible with 1/300th of a second.
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That was the part I wanted to show you.
Now the blur on LCDs is a different story, since the lights are on constantly and only the pixels change color at the given rate. But still you cann see the motion blur / dragging of the cursor even on a 144 Hz screen. Albeit much less noticeable than on a 60 Hz one.
If given a 60 Hz display side by side with a 144 Hz panel most people will be able to tell you which one feels more natural.
BTT: I don' think it will be a real poblem even if HTC does use a PWM module. Even though it might be somehow noticeable it won't disturb most people. Also: how often do you use your phone at the lowet brightness.
Yay! HTC 10 is PWM (flicker) free! Confirmed by Notebookcheck: http://www.notebookcheck.com/Test-HTC-10-Smartphone.164311.0.html (in German).
Oscillogram: http://www.notebookcheck.com/fileadmin/Notebooks/HTC/10/response_pwm.jpg
Just want to add that being able to notice it and it affecting you are two different things. Normally you can't notice neon lights flicker but they do and it will strain your eyes and make you tired. That's why bars have started to charge them out to leds.
Sent from my HTC 10
Glad I'm not effected by this crap. I'd hate having to pass on phones I really like just because they use PWM.
Sent from my SM-G935T using Tapatalk
Maybe an odd question for XDA, but a question I need answered before I pull the trigger on this phone. Earlier this year while buying a new television set, I learned that I am amongst a small minority of people who are sensitive to LED-lit electronic displays that use pulse width modulation to control brightness. Apparently, I can look at a PWM CCFL-backlit (i.e. my 5-year-old computer monitor or my Nexus 5) screen or a DCM LED-backlit screen (my television set) for hours with no issue whatsoever but I can only focus on a PWM LED-lit screen briefly before I start experiencing symptoms of eyestrain and motion sickness. It's like looking at a CRT that flickers because the refresh rate is set too low. Now I know an AMOLED lacks a backlight layer, but it still has to adjust for brightness, so if it uses PWM to do so, then I have to presume it will cause the subtle flicker leading to the same problems that I've experienced with LED-LCD displays. Is there anyone here who could possibly shed some light (no pun intended) on this issue?
Yes, it uses PWM. My suggestion is to buy the phone, and if it bothers you, utilize the return window where you will receive a full refund.
Hello everyone,
I got my device some time ago and wanted to highlight the things that rarely ever get mentioned by your average youtuber.
-) Yes, vibration motor noise is there.
But it feels really intentional, not like it is broken.
For me personally I don't mind it really, just wanted to share it since this is dicussed in this forum.
I don't have the "crackling" that has been mentioned, it feels more like when you set the alarm on an iPhone and rotate the hours/minutes wheel - satisfying.
-) Screen PWM'ing
The display is great, gets decently bright especially when viewing HDR content on YT.
Also the 120Hz is definitely a game changer, you can trust me on that.
What I however noticed coming from my F1 is the PWM.
Feels like they do 240-280Hz PWMing the brightness.
I feel like it is causing me headaches and sore eyes, but might just be the exhaustion after coming home from office work on Thursday's
Will see how it develops - my F1 has also PWM, but at around 4000Hz (!) which is definitely not noticeable.
Anyone of you have noticed the PWM? I might be an isolated case, even all high-end Samsungs's have 240Hz and no one complains ...
If you know a hack to enable DC dimming just shoot me a PM please
Hope I don't have to send it back because of this, would be really a shame.
-) Green tilt
Yes, I have noticed some green tilt at the upper half of the screen.
Only happens at really low brightnesses and with certain silver/grey'ish colors in dark mode with reading mode on.
But it is really minor, you really have to focus to make out a slight green shift.
That is no issue for me really, but wanted to highlight it because of the ongoing discussin.
Actually that was all.
The rest is great so far.
Extremely fast, premium build, nice AOD, battery is good so far, camera is more than enough for me and the sound quality is excellent.
If you want to me to test/check out something just let me know, as long as it doesn't involve ADB
Motor noise?
djuroue1 said:
Motor noise?
Click to expand...
Click to collapse
The vibration motor for the haptic feedback.
GeForce66 said:
The vibration motor for the haptic feedback.
Click to expand...
Click to collapse
Ah ok.I didnt hear that.
About Dc dimming:
I have read that they had problems with it, so it might not come to the stable version but it can be enabled in the developer version.
darkb7 said:
About Dc dimming:
I have read that they had problems with it, so it might not come to the stable version but it can be enabled in the developer version.
Click to expand...
Click to collapse
Any link you can share with me? Maybe there is a chance I can give it a try.
GeForce66 said:
Any link you can share with me? Maybe there is a chance I can give it a try.
Click to expand...
Click to collapse
It was stated about the K40 on Weibo by a Xiaomi official, but since it is the same phone as Poco F3 I guess the situation is no different.
Here is a link: https://en.xiaomitoday.it/redmi-k40-poco-f3-dc-dimming.html
Yeah so I have packed it up again and will send it back to Amazon.
Unfortunately the PWM does not go along with my eyes/brain.
But other than that, great device - can definitely recommend, just make sure you are not sensitive to PWM.
When does PWM kick in according to the brightness settings?
From what I have seen as soon as you are below 100%
PWM?
_j3roen said:
PWM?
Click to expand...
Click to collapse
This should explain very well: https://www.oled-info.com/pulse-width-modulation-pwm-oled-displays
Can you please help me.. I don't know if my eyes are sensitive to pwm or not as I've always used an ips and I don't have the option of returning the phone, I used to get a headache behind my eyes while using my old pc for a long time, so does it relate to it or did you have the same problem?
Well yes, it could be - or you just were in front of the screen too long in general.
For me only my eyes start to burn when i have work in front of the pc all day, but no pain behind the eyes. This only happens with PWM'd OLEDs it seems.
What monitor have you been using with your pc?
GeForce66 said:
Well yes, it could be - or you just were in front of the screen too long in general.
For me only my eyes start to burn when i have work in front of the pc all day, but no pain behind the eyes. This only happens with PWM'd OLEDs it seems.
What monitor have you been using with your pc?
Click to expand...
Click to collapse
samsung monitor b1930n, I used to get the pain after playing for long time. I then switched to a laptop (lenovo z50-70) and the frequency of the pain decreased a lot
I couldn't really find much information. If you have the chance just point a camera at the screen when set to medium/low brightness, if you see the flicker then your screen uses PWM.
To anyone wondering about PWM in the future, notebookcheck measured it at 490Hz. This should be fine for almost anyone.
My current phone Mi 9T has 240 and I did not even know it, so I'm good. Had me scared for a bit with the headaches and whatnot
This is a great phone and I am actually impressed by its display. It's so clear to the point that I enjoyed watching cricket matches on this phone. Great sounds as well, especially for the fact that it's not expensive.
Need assistance !
I'm planning to buy this phone since I'm done with my mi 10T .
Mi 10T having 1 issue which is the only reason i will let it go . The earpiece
has the ultrasonic technology which is annoying and unstable causing a lot of calling issues since there's no a proximity sensor . Even the WhatsApp voice notes having the same issues .
I have looked around for newer phone which i think poco F3 might be the one!
I have tried to look around if xiaomi still using that stupid technology init ! But no luck.
If ur facing proximity sensor issues please confirm since my birthday is coming on sept 18th and I will gify my self a new
Thanks
If you want to change because of the proximity sensor, give the F3 a wide berth. Whether the problem can ever be solved via software is written in the stars - and it is cloudy, very cloudy... I don't think Xiaomi will ever fix this issue.