MICHAELSD
macrumors 603
No, but compared to the 12 the max brightness of the panel may not be “artificially limited.”
Other Eye-strain while using iPhone X and up
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MICHAELSD
macrumors 603
I’d like to order a 12 Pro Max to try, since I’ve skipped OLED iPhones for the past two generations so I’m curious to see what changes Apple has made.
Funnily enough I was leaning towards the 12 Pro since I would like a smaller phone and I’m also trying to spend less time on my phone overall, but the Max is tempting.
The lack of store demos (although I assume if I walked into a Target right now they should have the 12 and the 12 Pro on display) may lead more customers to order and test at home, then swap for a different model/size. Not necessarily bad, but I think it’s a trend we’ll see. If by some miracle I don’t have issues with the Max or vice versa, that doesn’t mean the other models will work out to be okay so I’ll have to stick with whatever doesn’t cause headaches.
Hi guys! That’s my first message here. I’m from Russia and I’m in the same boat with you - have a high PWM sensitivity - few minutes enough for eye strain, and 10-20 minutes to get headache, now stuck with my 8plus.
I read a lot of threads in english and russian, and found something very interesting - wonderful video on Youtube from another russian guy, which with a special device measured not only the PWM frequency, which we already know a lot about, but also another indicator - the ripple coefficient (I hope that Google Translate will translate correctly).
Youtube video link
I will explain what this indicator means. The PWM frequency shows how many times per second the brightness of the backlight changes, for example 240 Hz - 240 times per second, and the ripple coefficient in simple words shows the difference between the maximum and minimum brightness values, in other words, the strength of the stroboscopic effect.
For example, the ripple coefficient of the Iphone 8 and Xr is from 0.7 to 1% at any brightness level, while the XS and XS Max models have a ripple coefficient from 7% at the maximum brightness level to 70% at the minimum (while there is also a peak 140% at 30% brightness - the most dangerous level of brightness for using the XS and XS Max).
For the sake of fairness, it should be noted that Apple has done a lot to minimize this effect - at brightness levels from 100% to 50%, the ripple coefficient changes from 7% to 10%, and only after the brightness drops below 50% it begins to grow rapidly. Galaxy Note 9, for comparison, already at 50% brightness has a ripple coefficient of 104%. Perhaps that is why for some people with an average level of PWM sensitivity, recommendations for setting reduce the white point and maintaining the brightness level above 50% work. But for people with high sensitivity, even at the maximum brightness level, the ripple coefficient turns out to be excessively high - 10 times more than models 8, 8 Plus, Xr, 11, and one and a half times more than prescribed by sanitary rules.
In Russia, we have sanitary rules that set the permissible limit for the ripple coefficient of lighting devices and screens, 10% for office premises, 5% for workers at computers (I think the same is for smartphones). Because at a high level of pulsation, negative effects on the eyes and nervous system can appear. This is exactly what we have when trying to use OLED iPhones - eye strain, headaches. These rules were inherited from the USSR, but times have changed, the USSR no longer exists, and corporate money has become more important than people's health, probably the same is happening in your countries. If in the USSR the Iphone with OLED screen were a device for work, then its use would be simply prohibited, but now this clearly unhealthy technology is presented to us as innovation and quality improvement.
And so, what to do - I saw several encouraging reports that some those who could not use X, XS Max, 11 Pro can use 12 either without an issue at all or with moderate issues. Maybe this is due to the refinement of the brightness control algorithm, which led to a lower ripple coefficient (I hope). I'm planning on buying a meter like the one the guy from Youtube video had on Monday, and then go to the Apple store and measure the ripple coefficient of 12 and 12 Pro at various brightness levels, including reduced white point.
If anyone is interested, I can post the measurement results here.
I read a lot of threads in english and russian, and found something very interesting - wonderful video on Youtube from another russian guy, which with a special device measured not only the PWM frequency, which we already know a lot about, but also another indicator - the ripple coefficient (I hope that Google Translate will translate correctly).
Youtube video link
I will explain what this indicator means. The PWM frequency shows how many times per second the brightness of the backlight changes, for example 240 Hz - 240 times per second, and the ripple coefficient in simple words shows the difference between the maximum and minimum brightness values, in other words, the strength of the stroboscopic effect.
For example, the ripple coefficient of the Iphone 8 and Xr is from 0.7 to 1% at any brightness level, while the XS and XS Max models have a ripple coefficient from 7% at the maximum brightness level to 70% at the minimum (while there is also a peak 140% at 30% brightness - the most dangerous level of brightness for using the XS and XS Max).
For the sake of fairness, it should be noted that Apple has done a lot to minimize this effect - at brightness levels from 100% to 50%, the ripple coefficient changes from 7% to 10%, and only after the brightness drops below 50% it begins to grow rapidly. Galaxy Note 9, for comparison, already at 50% brightness has a ripple coefficient of 104%. Perhaps that is why for some people with an average level of PWM sensitivity, recommendations for setting reduce the white point and maintaining the brightness level above 50% work. But for people with high sensitivity, even at the maximum brightness level, the ripple coefficient turns out to be excessively high - 10 times more than models 8, 8 Plus, Xr, 11, and one and a half times more than prescribed by sanitary rules.
In Russia, we have sanitary rules that set the permissible limit for the ripple coefficient of lighting devices and screens, 10% for office premises, 5% for workers at computers (I think the same is for smartphones). Because at a high level of pulsation, negative effects on the eyes and nervous system can appear. This is exactly what we have when trying to use OLED iPhones - eye strain, headaches. These rules were inherited from the USSR, but times have changed, the USSR no longer exists, and corporate money has become more important than people's health, probably the same is happening in your countries. If in the USSR the Iphone with OLED screen were a device for work, then its use would be simply prohibited, but now this clearly unhealthy technology is presented to us as innovation and quality improvement.
And so, what to do - I saw several encouraging reports that some those who could not use X, XS Max, 11 Pro can use 12 either without an issue at all or with moderate issues. Maybe this is due to the refinement of the brightness control algorithm, which led to a lower ripple coefficient (I hope). I'm planning on buying a meter like the one the guy from Youtube video had on Monday, and then go to the Apple store and measure the ripple coefficient of 12 and 12 Pro at various brightness levels, including reduced white point.
If anyone is interested, I can post the measurement results here.
Roadstar
macrumors 68000
Here’s one who’s interested in the results. It would be awesome if you can do the test and share your findings!
one more
macrumors 603
Please do, I am really curious to learn about your measurements! 🖐
TDDM
macrumors 6502
This is very interesting, I’d definitely like to hear your results as well.
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user1234
macrumors 6502a
This is interesting! The term used would be flicker percentage or percent flicker for modulation depth (difference between max and min light intensity). What confuses me about the measurements you refer to is that some of them are above 100%. That's not possible with flicker percentage since it can't be brighter than max or darker than no light. I'm not sure what that meter measures if it can present values like that.
It is however interesting because the amount of flicker together with the frequency is key to how one will tolerate it. I'd be very interested to see measurements of both the 12 and 12 Pro and to see if there is any difference between them. It can be difficult to get accurate readings with a lot of ambient light, so you need to carefully shield the measuring device so it doesn't pick up ambient light and reads the flicker of that or a combination of the two. I'm really interested in your findings!
It's also interesting that you mention a standard because there is an IEEE standard for flicker in light in work environments, or at least a recommendation. IEEE Std 1789TM-2015. It does not seem to be well known as flicker is still a huge problem for me in stores and office buildings.
MICHAELSD
macrumors 603
There were still offering demos via appointment when they reopened so I imagine they’d have the iPhone 12 models that have been released on display.
Admittedly I’d order an iPhone 12 Pro Max today if they had the extended holiday return policy in effect. I’m not sure 14 days will be enough to decide whether it’s a phone I’ll be able to continue using for the next year or two.
You are definitely right about being confused about a rate above 100%. I described it as simplified as possible to convey the main idea.
The formula for calculating the indicator looks like this:
Where E max is the maximum illumination value, E min is the minimum illumination value, E cp (cp from russian abbreviation of the word average) is the average illumination value. So it can be above 100%.
Example graphs (some letters in Russian):
I also do not like how Google translates the name of the term, literally this is the coefficient of pulsation (still not sure about the accuracy of the translation), you correctly grasped the essence of the meaning and described it very well - the PWM frequency shows the flicker frequency, and this indicator shows the amount of flicker. I suppose that we would not feel a issue if the screen brightness changed 240 times per second from 98% to 100% or from 48% to 50%, but this would lose the whole point of using PWM technology for manufacturers. This also indirectly confirms that the problem may not be in the flicker frequency, but in the amount of flicker, or in a combination of both.
But what do I hope for - if Apple was able to implement a change in the pulsation coefficient from 7% to 10% at brightness levels from 100% to 50% in previous models, which is not enough for many of us, maybe in models 12 and 12 Pro this figure changes from 1% to 3-5% at the same brightness levels, which may already be more acceptable for use, at least at the maximum brightness level with the use of reducing the white point to control the brightness.
Thank you for your advice about the accuracy and possible difficulty of measurement, I read the same in the instructions on the device manufacturer's website - it is recommended to bring the photosensor as close as possible to the measurement object, while the photosensor should be directed towards the measured object in order to exclude the influence of other light sources. In general, this is possible to implement because the photosensor has a rotary mechanism. I think I can practice on my 8plus in natural light and then check if there is a difference in the reading when measured inside the store.
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user1234
macrumors 6502a
I see, so it's kinda like flicker index in that it takes the max and min into consideration compared to the average, but in a different way. Flicker index is calculated by (Area1) / (Area1 + Area2) where Area1 is the area under the curve but over the average, and Area 2 is the area under the curve and under the average.
According to most of the little research there is, 5-10% flicker should be tolerable for most. I would love if manufacturers stop using PWM but LEDs aren't stable in terms of color at low brightness with DC dimming unfortunately. I can't use OLED/MicroLED devices until they are almost flicker free at any brightness.
Good that the manufacturer have proper instructions on measurement. That is not always the case. I think bright the sensor really close and shielding it with your hand should work fine. I would also get a reading of the ambient light to see what potential amount of flicker it would interfere with.
Looking forward to the results! 👍
And so here are the results of measurements:
Brightness level - pulsation coefficient (may be better translation from Russian is flicker index)
Iphone 12 Pro
1. 100 % - 6.8 %
2. 75 % - 7.7 %
3. 50 % - 8.6 %
4. 25 % - 10.0 %
5. 0 % - 8.3 %
Iphone 12
1. 100 % - 6.8 %
2. 75 % - 7.7 %
3. 50 % - 8.9 %
4. 25 % - 9.5 %
5. 0 % - 8.3 %
For comparison:
11 Pro Max
1. 100 % - 6.8 %
2. 75 % - 7.8 %
3. 50 % - 8.3 %
4. 25 % - 80.2 %
5. 0 % - 71.1 %
8 Plus
1. 100 % - 0.7 %
2. 75 % - 0.7 %
3. 50 % - 0.8 %
4. 25 % - 0.8 %
5. 0 % - 0.9 %
Conclusions: 12 and 12 Pro are similar to 11 Pro Max at brightness levels from 100% to 50%, but much better at brightness levels from 50% to 0%, and are still significantly different from 8plus, which does great at any brightness level.
This probably explains the fact that some of those who could not use the X, XS, 11 Pro can use the 12 and 12 Pro. It is likely that this is possible in people with moderate sensitivity to PWM.
Below is the measurement results for the reduced white point:
iPhone 12 Pro
White point 75 %
1. 100 % - 7.9 %
2. 75 % - 10.5 %
3. 50 % - 14 %
4. 25 % - 15.6 %
5. 0 % - 12.6 %
White point 50 %
1. 100 % - 7.2 %
2. 75 % - 9.2 %
3. 50 % - 10.8 %
4. 25 % - 12.6 %
5. 0 % - 9.8 %
iPhone 12
White point 75 %
1. 100 % - 8.5 %
2. 75 % - 11.5 %
3. 50 % - 13.1 %
4. 25 % - 14 %
5. 0 % - 12.1 %
White point 50 %
1. 100 % - 7.5 %
2. 75 % - 9.1 %
3. 50 % - 10.7 %
4. 25 % - 11.6 %
5. 0 % - 9.8 %
Conclusions:
For those who plans to give a chance for the 12 and 12 Pro, I recommend not using the white point reduction, but leaving the white point at the standard settings, as this makes the flickering not better, but even worse. Also, if possible, you should avoid a brightness level around 25%, because all OLED iPhone screens have a peak flicker value at this brightness level.
It should also be noted that Apple heard many reports of issues with the use of OLED screens and did what they could.
For comparison, I measured the new Samsung S20 Plus, as I was wondering if there is a difference between 120 Hz and 60 Hz. The results were terrifying - at brightness levels from 100% to 50%, the pulsation coefficient (flicker index) was from 40% to 110%, and right in a matter of 1-2 minutes of use, I immediately felt how all the typical negative effects from PWM arise. It also turned out that the pulsation coefficient is approximately the same at both 120 Hz and 60 Hz. It was interesting for me whether I should not buy a new iPhone now, but wait for next year, when new models with 120 Hertz screens will be released.
Personally, I plan to wait for the 12 Pro Max to start selling, measure and buy it if its flicker index is at least the same as that of 12 and 12 Pro. I hope that both I and many of you will be able to use the new 12 and 12 Pro quite normally.
Roadstar
macrumors 68000
Awesome, thanks for the results! That Samsung number sounds scary, and I can’t help but wonder what the OnePlus 8T would score in the same test as just today I spotted this comparison: https://www.phonearena.com/reviews/OnePlus-8T-vs-Samsung-Galaxy-S20-FE_id4880
The interesting part there is this:
That explains why OnePlus doesn’t seem to offer the experimental DC dimming software feature anymore. Wonder if this also explains the rather high PWM frequency rating (around 450hz) for the 8T.
Yes, it is really very interesting!
I would not like to switch to Android, but it is interesting to know, what technology can do now, if the manufacturer really wants to take care of the well-being and health of customers.
I don't know if there are 8T demo samples in stores. If there is, it would be interesting to measure its pulsation coefficient (flicker index).
Am I reading this correctly that on the 12 and 12 pro, the flicker pulsation coefficient is actually best at 100%, that someone who is sensitive would be best at that level? And obviously that is so bright it would hurt the eyes just due to the brightness, so the best according to this data for sensitive folks seems to be 50% brightness with 75% white point?
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TDDM
macrumors 6502
Thanks so much for doing the tests, this is very valuable information and looks like it may be the first real breakthrough we’ve had in figuring out exactly what’s causing the issues.
On a related note, certain people are also sensitive to the XR/11/iPad Pro 2018/2020, iPad Air3/4, etc screens, would it be possible to test any of those as well the next time you’re able to? I’m very curious if they have higher percentages than older devices like the 8+, older iPads, etc.
Yes you are right. There is still some difference between the brightness level of 100% and 5%, but it is not as huge as the 11 Pro Max and other similar previous OLED models. In this regard, the 12 and 12 Pro are not ideal, but are more stable at different brightness levels. For some, this will still not be enough, but someone will be able to use.
This is fantastic information -- thanks for sharing it. Do you happen to have access to an X or XS that you can do the same measurements on as a baseline for comparison? I can't look at my wife's XS for 30 seconds without feeling it, but would live to explore trying a 12 Mini if the difference is enough.
Yes, it is really interesting that this is confirmed by the data, since I have met several times how people who are not sensitive to PWM scoffed, saying that this was all fiction or psychological problems.
I tested the regular 11 also, it showed the same good results as the 8 Plus. I also saw messages from some of those who normally used 8 Plus, reported issues when using 11. Perhaps this is somehow related to a lower PPI or a narrower screen and because of this, a smaller font on the standard settings. I also noticed that the regular 11 has colder colors even with True Tone enabled, while the 8 Plus has significantly warmer colors with True Tone enabled. Many manufacturers or software tools now suggest filtering the blue spectrum, especially in low light, as it can negatively affect the eyes and well-being.
I felt quite normal holding the regular 11 in my hands, but it was very revealing for me when I took the Samsung S20 Plus - in a matter of moments all the negative effects of PWM were felt.
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My wife has an XS Max, and for me this is a completely creepy device.)) When she asks for help with some settings or teach how to do something, I turn on the maximum brightness and do it as quickly as I can.)) Will definitely measure her phone also.
A-MEN! The XS is a creepy device indeed. When my wife asks me to look at hers to fix something, or read a FB posting, I have to do very quick. No kidding, 2 minutes of reading a FB post last night on it gave me eye issues for 5 minutes afterwards.
I agree, same with my wife's XS Max!
I played around with a 12 in the store for about 5-10 minutes last weekend and had no problems like I do on my wife's XS Max.... I know that was a very small slice of time, but I have my fingers crossed that my Mini that is arriving this Friday will be OK for me. I will try adjusting brightness up to around 50%, and then using reduce whitepoint to keep it from being too bright (I am sensitive to brightness), hoping to find the right compromise per the great data presented here, to make it usable. Fingers crossed!
At 50% brightness with 75% white point the pulsation coefficient is 13.1% (iPhone 12), while at standard white point settings even the maximum pulsation coefficient is 10% (around 25% brightness). Therefore, it is probably advisable not to use white point reduction in 12 and 12 Pro. It will be better to simply lower the brightness down to 0% (although of course in completely dark rooms this will still not be enough and the screen will be too bright, then you still have to reduce the white point and try to find the right compromise). Apparently, in order to maintain color accuracy while reducing the white point, the manufacturer is forced to increase the pulsation level. Good luck with trying! I also have my fingers crossed awaiting of the start of sales 12 Pro Max.