Alright. After I bought the S20 Ultra, while using it, I felt pain in my eyes, migraines, dizziness and other problems that appear only if you look at the screen. I went online with this problem and found that the PWM ripple ratio very strong in the S20 line. The ripple coefficient is 40-50% at MAXIMUM brightness, which exceeds the safe ripple rate of artificial lighting set by different countries by 2-3 times. At a brightness of 60% or less, it is about 130-140% which are just huge values. At the moment, this is the worst result on the market. In a smartphone for 1000 euros. Such huge values combined with a large screen can cause the above problems not only for people who are sensitive to PWM, but even if you have never felt any problems with Amoled screens before (like me). In addition, due to this amount of pulsation at low frequencies, your pupils constantly narrow and expand slightly, which greatly strains the eye and can worsen your vision, especially if you are sensitive to PWM. Samsung needs to introduce a DC-Dimming function or its equivalent that reduces flickering and does not play with the health of their users.
I’m glad I came across this even though I’m kinda late. But I’m in the US and I agree that this phone has caused nothing but issues for my eyes. Especially with the lockdowns and unemployment I’ve been using it way more then I normally would, granted, but I’ve done so with other phones in the past without much issue. Now I have weird ghosting images in my eyes, sometimes I have weird shimmering/fast pulsating vision (and it’s not my heart beat, I believe it’s from the pulsating screen and the pupil basically learning to constantly adjust to stuff) and I’ve also noticed that my eyes in general are just weird. I react way more to LEDs now more then ever as well as if my eyes are basically done with dealing with light. This has also effected my driving because my eyes are constantly adjusting for no reason!
whats sad is the only phones without it is iPhone (up until the 11). All other phones have it unless you want a super outdated operating system. I found the LG G7 has the highest PWM with a semi-new operating system (android 9, sometimes 10 - and we’re on 11 now), but honestly it’s frustrating because all the brand new devices have this issue. Even the S21 has it, even the Note devices have it!!! My S10+ had it but i guess it’s a little higher rate so I never got effected. I think I’ll just have to either get that older LG or even switch to stupid apple 😭
also I confirmed this by using my laptop that’s confirmed a 0 PWM rate, and using my grandmas old iPhone that has a 0 rate for awhile too - my vision has gradually gotten better so far but now I’m just p*ssed that I have this S20+ that’s basically useless
Unfortunately the hz is a lot different then the PWM rate. I believe the S20 lineup is around 214 at pretty much any brightness level. I tried on my S20 to set the brightness at 100% and use this app called OLED SAVER to reduce the brightness artificially, it still had the same amount of flicker with the app off and the app on - meaning it’s just too low even at full brightness. Anything below 250 you’re gonna have issues. Above 500 is ideal but good luck finding anything with that other then a iPhone X. Unfortunately in the android realm the best bet is almost nothing. Even the old S9 technically has bad flicker, but mainly at lower brightness settings. So it all depends!! If you really need an upgrade you’d have to go with an iPhone X and ditch android unfortunately
I wish I realized it was my phone causing issues before my return period ended. Now I’m stuck with a paperweight unless I convince someone to buy it from me private party