Develop Bugs

[Q] Does the Galaxy Note 8.0 have PWM?

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!

HTC 10 screen flickering (PWM)?

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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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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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

Do the Pixel/Pixel phone displays use PWM?

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.

Android P what have they done with the brightness?

Just installed P and now previous brightness level of 63 it's so dim? I have to have it almost on 90% brightness now, why have they messed with this, it was fine as it was

Ady1976 said:
Just installed P and now previous brightness level of 63 it's so dim? I have to have it almost on 90% brightness now, why have they messed with this, it was fine as it was
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Same for me. WTF Google?

The actual brightness is the same, they just changed how the slider works. The first half moved it fast, last half moved it slower. Now the slider is more uniform.

https://www.androidpolice.com/2018/...c-brightness-slider-introduced-android-p-dp3/
Sent from my Pixel 2 XL using Tapatalk

It's definitely not smooth across the entire range, all my brightness is almost all the last 10% and actually a pain to set properly, it's worse for me.

That's more accurate because in bright indoor lighting or outside it's going to be towards the end of the scale. Dim indoor lighting I'm currently at 43%. And in pitch black it goes to 0%. I pretty much never touch my slider anymore after a couple adjustments. Don't get caught up on the percentages. I would be willing to bet that with Oreo at 40% and Pie at 90% the lumens output of the screen was the same.
Ady1976 said:
It's definitely not smooth across the entire range, all my brightness is almost all the last 10% and actually a pain to set properly, it's worse for me.
Click to expand...
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Sent from my Pixel 2 XL using Tapatalk

EeZeEpEe said:
That's more accurate because in bright indoor lighting or outside it's going to be towards the end of the scale. Dim indoor lighting I'm currently at 43%. And in pitch black it goes to 0%. I pretty much never touch my slider anymore after a couple adjustments. Don't get caught up on the percentages. I would be willing to bet that with Oreo at 40% and Pie at 90% the lumens output of the screen was the same.
Sent from my Pixel 2 XL using Tapatalk
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Yeah I don't touch mine once it is setup generally but it's definitely not even throughout the scale, only gets really bright from like 85% onwards, just seems odd the real brightness is so high up, makes for fine tuning a bit difficult.

The screen has been rated a minimum of 1.78 nits and a maximum of 496 so if it truly is linear now, 50% is something like only 247 which isn't that bright at all.
Ady1976 said:
Yeah I don't touch mine once it is setup generally but it's definitely not even throughout the scale, only gets really bright from like 85% onwards, just seems odd the real brightness is so high up, makes for fine tuning a bit difficult.
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Sent from my Pixel 2 XL using Tapatalk

Hi
So much for AI on adaptive brightness, it's rubbish, and why do Google try to fix things that aren't broken, who needs AI for adjusting a backlight? Seems nothing more than just being able to market the phone as having AI! Never had an issue on Oreo, had it set at 25% with adaptive brightness and it was always the correct brightness wherever I was, which shouldn't be difficult given it's got a sensor to read the light levels.
Now since Pie, last night I turned my phone on in the dark and was blinded by a bright display (Oreo it would have been at it's lowest level in the dark), so turned the brightness down, turned it again later and the same thing, way too bright, and again this morning in a fairly dark room the same thing, far too bright, so I turn it down again. How long will it take to learn? The old method it was tamed immediately, now I'm constantly fiddling with the brightness, how is that progress!
Is there an option to go back to the old method?
Wish I hadn't bothered upgrading, just another year with an Android update with changes for changes sake.
Regards
Phil

PhilipL said:
Seems nothing more than just being able to market the phone as having AI!
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Totally agree on this. Adaptive battery and adaptive battery are almost non-sense. Only something cool to brand the item.
And Pixel Visual Core is just something super-expensive to make Whatsapp, Facebook and Twitter cameras use HDR+. I'd rather pay something less and not having this feature that is probably expensive (or modifies the perception of the Pixel 2 as super-new and mega futuristic). Also, I've got the feeling they won't use it for Pixel 3 or 4.
Moto X1 was the last to use more CPUs to optimize the phone, before Qualcomm introduced more chips.

Hi
For any one having this issue please report this from your device at Settings > System > About Phone, the more people that flag it the more likely it will get fixed.
For me, I hate these updates that break simple basic functionality and overall add nothing extra to what we had with Oreo. Google really need to test these things properly and stop trying to fix things that simply are not broken!
Regards
Phil

PhilipL said:
Hi
For any one having this issue please report this from your device at Settings > System > About Phone, the more people that flag it the more likely it will get fixed.
For me, I hate these updates that break simple basic functionality and overall add nothing extra to what we had with Oreo. Google really need to test these things properly and stop trying to fix things that simply are not broken!
Regards
Phil
Click to expand...
Click to collapse
Already reported, i shouldn't have to have my phone on 90% to be the same as what it was on 63%

Weak/dull max screen brightness in Pie with manual mode (no auto!)

Hi Guys! i just bought an S9, and its very new, made in march, came with Pie.
I find the maximum manual brightness setting to be way weak and dull for my taste.
Average lit room in the daytime, chrome browsing, evernote editing etc.
When the background is white.
I tried out an s8+ and an LG V30 in the last few weeks, had those on my hand, and they had way stronger brightness and starker whites on normal mode. I had to lower them to ~80% to be comfortable.
This completely baffles me as all the reviews stated that s9 has higher NIT than the above phones.
Grateful for advice. shoud i try another factory rom, downgrade to oreo, or up to the newest pie?
Or is this a hardver limitation and cannot be changed?
thx for any info! :highfive: :good:
ps: i googled but everyone is talking about the AI auto brightness mode, tried that, that doesnt change the available maximum, only in direct sunlight.

kbuss said:
Hi Guys! i just bought an S9, and its very new, made in march, came with Pie.
I find the maximum manual brightness setting to be way weak and dull for my taste.
Average lit room in the daytime, chrome browsing, evernote editing etc.
When the background is white.
I tried out an s8+ and an LG V30 in the last few weeks, had those on my hand, and they had way stronger brightness and starker whites on normal mode. I had to lower them to ~80% to be comfortable.
This completely baffles me as all the reviews stated that s9 has higher NIT than the above phones.
Grateful for advice. shoud i try another factory rom, downgrade to oreo, or up to the newest pie?
Or is this a hardver limitation and cannot be changed?
thx for any info! :highfive: :good:
ps: i googled but everyone is talking about the AI auto brightness mode, tried that, that doesnt change the available maximum, only in direct sunlight.
Click to expand...
Click to collapse
My S9's screen is very bright in almost every situation. Even in sunlight, I can see everything clearly in auto brightness. Indoors I just keep it below 50% and it's still plenty bright. Try reporting this issue or go to a samsung service centre to fix it or replace your phone....
Wait, do you use any kind of power saving? Because in power saving mode there's an option to reduce the brightness 10%, make sure it's off.

jamil aboudaher said:
My S9's screen is very bright in almost every situation. Even in sunlight, I can see everything clearly in auto brightness. Indoors I just keep it below 50% and it's still plenty bright. Try reporting this issue or go to a samsung service centre to fix it or replace your phone....
Wait, do you use any kind of power saving? Because in power saving mode there's an option to reduce the brightness 10%, make sure it's off.
Click to expand...
Click to collapse
no and like i said its on manual, maxed out.

guys i just looked into a measured review of the screen brightness.
can it be that when the whole screen is white, its actually less bright than the s8?
340 vs 403 nit?
(the titles are not in english thats why i blurred them )