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iPhone X PWM (Flicker) and New iPhones
- Thread starter kerplunknet
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PWM causes eye strain/headaches for me so it’s definitely a concern for me.
However, the iPhones 7/8 don’t use PWM but still have a LED backlit display. The LCD version of the new iPhone will likely not have PWM.
That said, the question I have is: for those who are sensitive to PWM, will Face ID cause any issues?
I don't think Apple will increase the refresh rate on the iPhone XS, because I believe that it would increase battery consumption. And since headaches due to PWM is an issue for a small percentage of people, I don't think Apple will be willing to sacrifice battery life.
For those of you who suffer from this, under what settings and after how much time is it apparent? Trying to figure out if you can find out if you are susceptible to this with just a few minutes' playtime in the store or if it doesn't happen until after a couple hours.
For me it took me awhile (a couple of months) to realize my symptoms (eye strain, headaches and even on bad days migraines) were due to the phone screen. It was basically a process of elimination to determine it was from a phone screen or other various factors. Now that I’ve gone through that process, I can usually tell within about 20-30 minutes of use. Usually the issue for me is that the display is too bright so I have to lower the brightness. A lot of displays at 100% brightness have 0 PWM and it doesn’t kick in until you get to lower brightness settings. I’ve found that with AMOLED/LED screens I need the brightness <50% and sometimes even <20% and at this low of brightness the symptoms are very apparent almost immediately.
It's very likely the new 6.1 LCD model was built for this very reason. Apple engineers and executives use iPhones too obviously, and it's a sure bet that some of them can't tolerate PWM flicker either. Apple will never publicly admit that the LCD model is a fallback for those who can't tolerate OLED PWM, but my hunch is that's the reason for its existence. Marketing is giving it a spin as the "price conscious" iPhone cuz they're eliminating some unnecessary features too, but I think that's just a ruse.
iPhones have used LED backlights since the first one in 2007. The X was the first not to. I don't expect to have any issues with the LED iPhone but it is said to have a different type of thinner LED backlight. This shouldn't change the driving though so I fully expect it to still be fine.
It's a lot easier to use analog dimming when all LED's run at the same brightness rather than being matrixed and run at different levels like with OLED and Micro-LED.
It differs a lot.
For me it depends on my daily shape. If I have slept to little I will usually get symptoms within seconds, but if I'm well rested and in good shape it may take days before I notice any symptoms. That's why it's so difficult to determine if something is going to work long term or not, because I may not know before the return window is up.
With the iPhone X I felt slight motion sickness after about 5 minutes the first time I looked at it in a store. Subsequent exposures have had mixed results again depending on daily shape. I can't use one daily so it's off limits for me.
I thought the same, but it’s not really a viable alternative as it will probably be missing too many features that are on the OLED phones. I need an LCD screen but it must be the latest camera etc. or it won’t be worth upgrading from my current 8 - unless the dual SIM rumour turns out to be fact.
I agree. I will settle for the LCD version but what I really want is an X with an LCD display. Telephoto lens, 3D Touch, stainless steel frame and all the other things the X had except for the display. I hope we will get to a PWM free technology again, but I think it will be a few years unless Apple has something up their sleeve with PWM free OLED/MicroLED.
I have PWM sensitivity too. It's really frustrating, I've never had any problem like this before with my eyes. I'm really disappointed about having to settle for the budget phone since I've been waiting for a huge iPhone like the XS Plus for *years* now.
I'm actually quite surprised that Apple didn't go any higher than 240Hz, I would've thought they'd be the company who would care about those small things.
I'm actually quite surprised that Apple didn't go any higher than 240Hz, I would've thought they'd be the company who would care about those small things.
Basicly all AMOLED are ~250Hz or less except some LG screen in 2015, which had different issues.
It seems to be a technological limitation at this point. I don’t know if it’s impossible to get it faster at the moment, or if the R&D involved in getting it higher is deemed not worth the effort. I have heard that many still have issues at 1000 Hz so I’m not sure how much it would help to increase the frequency unless it’s super high. I would like full analog control, but doing that on every individual subpixel is probably both costly and hugely space consuming. Hopefully we will get there soon.
It’s a bit weird that flicker is accepted with OLED since flicker free computer monitors are gaining traction in offices. I bought a computer monitor that was maketed as flicker free and tested at 0 flicker when I got really bad symptoms from my prior monitor, which had really bad flickering clearly visible with a phone camera. I’m now in the process of building a sensor for flicker testing of both displays and LED light sources like LED bulbs and strips.
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Ok, so I'm going to rant here for a bit. Please bear with me.
It may be the easiest way, but the most accurate way is a light sensor hooked up to an oscilloscope. If the flicker frequency happens to be in sync with the frame rate and shutter speed flicker may not be seen even though it exists. I'm using a BPW34 miniature solar cell which I'm planning on connecting to a computer running a software called Soundcard Oscilloscope. It will not allow me to calculate the flicker percentage as it will not give me an amplitude reference, but I will be able to see the frequency of the flicker if there is any. As soon as I have built an enclosure for the miniature solar cell, I will start testing on all of my devices. Both those who are giving me problems, and those who are fine, so that I can understand what works for me and what doesn't.
The reason I'm sharing this even though it may technically be off topic is that measuring is the only effective way to learn what causes issues and what doesn't. With this knowledge I will hopefully be able to test things before I purchase, or at least within the return period. This is the length those of us who are most sensitive have to go through to not have issues with LED lighting and OLED panels becoming the norm. TV panels have had these issues for years, and it can be a complete nightmare to find one that works well.
I agree that Apple should put effort into getting rid of PWM. They did it with their computers a long time ago, with their iPhones at some point (not sure when iPhones got rid of PWM if they ever used it in those) and I think they should invest some of their R&D into getting OLED panels to be flicker free. The same goes for the Micro-LED panels they are rumored to be interested in. They use the same principle of operation as OLED so the same R&D would be applicable there.
What frustrates me the most is that the big tech companies doesn't acknowledge this issue. If we assume that the estimated 10% of the population being sensitive is accurate then 10% may be a relatively small percentage of Apples users, but with over a billion of active devices this would be millions of users even though many users have multiple devices. I don't know how to get the attention of those who can make a difference with this issue. There has to be employees of both Apple and Google who can't tolerate OLED, and yet both these companies are going all out on OLED. Do they not care?
Reviewers are not making the situation any better either, raising OLED devices to the sky while complaining over LCD displays. For the end user this does not make a big difference. I would assume that the number of users who truly care and won't settle for LCD is relatively small. Apple use some of the best LCD panels available, and they have kept pushing this now very mature technology to make it great. I think these tech giants are afraid to use LCD panels because they don't want to get bashed by reviewers and have poor sales. Yes, OLED can technically achieve better color accuracy, works well with HDR, and has blacklevels that LCD can't compete with. I can however say that the amount of times I have looked at any of my LCD devices in the dark lately and noticed black not being 100% black is 0. If I look for it I can see it, but under normal use it's a non-issue.
Any ideas how we can raise the issue? A petition? An open letter? Both? Something else?
Rant over.
On topic:
I have no hope that this years OLED phones will have gotten rid of the PWM, or even have increased PWM frequency. It's LCD for me all the way. I would possibly like an Apple Watch, but I didn't realize until yesterday that they too use OLED so that will take some careful consideration.
IIRC, no iPhone before the X has used PWM. That's why there seems to be a decent amount of people suddenly realizing they have issues with PWM. I'd assume that for a good percentage of them (myself included), the X was their first experience with an OLED device that they were using frequently.
Yup, that's pretty confusing to me as well. I definitely understand that Apple has to prioritize which features/issues to work on, but it's surprising that they're okay with shipping a product that a good amount of people just flat out cannot use comfortably.
Hardware wise? Agreed 100%. Software wise though, not sure. Galaxy S7+S8 users were able to create a custom kernel that disabled the PWM on their devices, so it's theoricially possible to solve this with software. *Maybe* Apple could include something like that for this year?
I wouldn't worry about the watch unless you have severe PWM sensitivity. What makes PWM on phones an issue is that you're staring at the screen for a decently long amount of time, and that leads to the eye strain, headaches, etc. You rarely would use the watch for extended periods of time like that, so I think most PWM sensitive people would be fine.
For example, I've had an Apple Watch since early 2016, and had no issues whatsoever with the PWM. It also helps that most of the screen is totally black, which limits the flickering intensity.
That's exactly why I think the Apple Watch will work for me. It's small, so the amount of light is limited and unless used in darkness it only accounts for a very small amount of the light that reaches the eye. As you said it's also showing mostly black so there's even less flickering light. And the short periods of viewing time and the fact that it doesn't cover that much of the view.
It's great to know that it works for someone who is sensitive. It gives me more confidence that it may work for me too.
https://blog.elcomsoft.com/2018/03/...to-stop-oled-flickering-in-just-three-clicks/
Found the above which was interesting
Found the above which was interesting
I collect flashlights and people are put out when their sub $50 light has pwm measured in kHz. That we’re dealing with this on a piece of advanced electronics is absurd.
What ? You do realize LED is LCD and that’s been being used for a while nothing new... facepalm ....
For the same reason Apple does a lot of work on accessibility for the even smaller userbase who have very specific physical disabilities.
If we would say "why bother for the few" then why bother with VoiceOver, because that's a fairly small group with visual limitations. And Switch Control for those with extensive physical motor limitations? That's a tiny number of their userbase.
The reason why they should bother is because they obviously don't want to exclude anyone given their work with accessibility, so why exclude as much as 10% of the population (which is not that few)? So far there are models with LCD to chose from, but if the rumors are true (and I'm going to assume they are at this point) then the LCD Model will miss out on many features of the current X. And who knows if there is even going to be an LCD model next year or the year after as OLED production scales up and cost comes down.
So your flashlight has 10-bit colors HDR uniform over several millions of LED? Maybe there is a reason they just don't crank up the frequency.
And there you go they have a model for you with the LCD models. Voice over is a fairly simply fix. PWM is a hardware limitation not software. And once again they have a solution go buy the LCD model