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Higher PMW

(Topic created on: 28-02-2023 04:34 PM)
13781 Views
Adi0
Big Cheese
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A Reddit post from u/lamVenom_007

 

Why smartphone companies don't care about DC Dimming and PWM flicker?

Samsung talks about eye comfort etc. but this is the biggest eye comfort issue. Please add software DC dimming like other phone brands have it.  240Hz PWM

The Samsung Galaxy S21 in minimum brightness the display dropped to just 120 Hz, which is very low but at least constant. With increased brightness the PWM frequency varied between 227 and 250 Hz with a constant 240 Hz at maximum brightness.S22 and S23 also only have 240Hz PWM dimming at any brightness, which is far lower than BOE's 2160Hz and Samsung E6's 1920Hz, which is very harmful to the eyes of Samsung users, especially in low-light environments.

 

**• What is Dc Dimming and PWM flickering?**

 

 

[Here's](https://www.gizmochina.com/2019/04/03/what-is-dc-dimming-why-its-important-for-amoled-smartphones/) a short and sweet explanation on this topic.

 

To summarize, screen flashes on OLED panels heavily when the screen brightness is set to less than 99%

 

The lower you go from that percentage, the more you will experience it. With the naked eye, it's not noticeable but with another smartphone camera, you can observe what's going on on your screen.

 

 

**• Why we should talk about it?**

 

 

To focus correctly on the screen our pupil needs to adjust (grow big or small very quickly). It's like someone is turning on and off a tiny torchlight in front of your eyes.

 

The way I see it, it's already hurting people with sensitive eyes. Which is around 10-12% of smartphone users. Approximately 700 million people. It's common to have them nowadays. The condition will be worse for people who stream videos, play a lot of games, or read books on their phones. You cant always keep the brightness at a higher level while using your phone indoors and at night.

 

 

**• What is the solution?**

 

 

Now all these problems regarding screen flickering in OLED can be partially solved by simply turning on Dc Dimming. It will decrease the sharpness of the screen(not that noticeable) in low brightness situations and will save you from all these hassles by emulating like a display without PWM (or very high PWM). When you go past 50%-99% (depending on the device), Dc Dimming will go away and the screen will work normally. You can also use apps like OLED Saver and PWM free to get rid of it. But these apps are old and come with their problems.

 

The best solution is to make screens with a higher PWM rate to reduce the chance of detection. But OEMs do not care about it. Read here:

 

https://www.notebookcheck.net/Analysis-DC-Dimming-vs-PWM-Can-you-dim-AMOLED-displays-without-the-fli...

 

 

 

**• What companies are doing about it?**

 

OnePlus was the first company to implement that feature and some others(e.g. Xiaomi) followed them. The issue is they are too inconsistent. They put this feature in an update and the next update it's gone. I'm guessing they thought of its significance and then they found out people don't know or care about it so they just excluded it. No one's taking it seriously.

 

 

**• Why this post?**

 

Went to the doctor yesterday to check why my eyes are irritating me. Doc asked me if I was using my phone in low brightness and I replied "yes, I keep the brightness between 30-40%". He warned you are not the first person I encountered with this issue and the problem might be with your phone.

 

 

**• Conclusion** 

 

OLED is great. The sharpness and contrasty looks are cool! But it comes with its problems. I only wish smartphone companies were caring more about our eyes by getting rid of lower PWM speed. If you're suffering like me go for a device with an LCD screen. Alternatively, you can check if the device you're trying to buy support Dc Dimming/Anti-flicker or if it possesses a PWM that won't mess with your eyes.

 

I had problems with the latest iPhones and Samsung devices. Most likely you'll too. Research before you buy a device and please raise awareness to fix this. Thank you 

 

 

 

Here's more if you want to learn in detail :

 

https://www.dxomark.com/flicker-the-display-affliction/

 

https://www.notebookcheck.net/Why-Pulse-Width-Modulation-PWM-is-such-a-headache.270240.0.html

 

https://onezero.medium.com/is-your-phone-giving-you-a-headache-oled-screens-might-be-to-blame-a91213...

 

Video of my phone screen :

https://streamable.com/8gnm3p

 

A test: 

https://youtu.be/JjGJX6H_Yw0

.....................................................................
Thanks on the help! S24 Ultra owner.
4 REPLIES 4
Averageusers
Apprentice
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Thank you for this post, more content will help the topic.  I had to return my Samsung S23 Ultra, as the PWM Frequentie was again very low. 

After checking with Samsung some employees simple mentioned it was higher or no replies, so I guess there is no wide spread policy from Samsung on it, or they are aware of the problem and don't want to  adress is, as they currenlty don't provide a solution. I wonder why  a company like Samsung with the (best) Screens doesn't implement an software feature to reduce PWM flickering or use the high frequency screens (E6) 1900+ PWM on their premium phones. Even if only 1 or 2 % of the market suffers from low PWM frequency sensitiviy. If they made a software feature or screen that can reduce or eliminate the flickering, they would attract this group directly towards Samsung for the comming x years. As there is no (No Chinese) alternative.  (I would love a DC dimming option and accept the minimal screen quality drop). 

For more info on PWM/Dithering and flickering I recomend: 
https://www.dxomark.com/flicker-the-display-affliction/

https://www.notebookcheck.net/PWM-Ranking-Notebooks-Smartphones-and-Tablets-with-PWM.163979.0.html

Gobon1
First Poster
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I used to use Xiaomi phones before, I never paid attention to pwm, DC dimming was always turned on. Yesterday I bought an s23 ultra, after a few hours of use, my eyes started to hurt, I started looking, and I was very surprised that such a phone does not have DC dimming, now I don't know what to do, the screen **bleep** a lot of pressure on my eyes.

Osmanius_Prime
First Poster
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1.What Reason did you mentioned when you returned phone?
2.What seller told you and did they accepted that as a resson for return?
3.Did they returned you money or ...?

I went from S22U to S23U,and display on S22U was better for me,
On S23U my eyes are getting tired, little headaches...

Averageusers
Apprentice
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Returned it with without issues and gave feedback on de PWM issue, and this was the one reason I had to return it. same for the S 22.