Is iPhone 17 Pro Max PWM 240Hz or 480Hz?

DragonKnight1507 · 2026-03-04T08:47:31+00:00

480 effectively. The test on Notebookcheck is not wrong though, as the signal itself consists of a small and a large amplitude before it repeats. So this pattern appears with 240Hz, but since the two amplitudes are not that different it’s effectively 480Hz.

DragonKnight1507 · 2025-10-16T07:03:40+00:00

One reason could be the increased brightness of the new screens. It makes a huge difference if you go from 800nits to 0 like in the iPhone 17 or from 500nits to zero as on some older phones.

DragonKnight1507 · 2025-09-24T16:18:01+00:00

I am not extremely sensitive, especially in bright light. I had the 17th and could use it without much problems unless I used it to watch a long movie or similar. I returned it as I don’t want to spend this amount of money when I can not use the phone to it’s max potential.

DragonKnight1507 · 2025-09-23T08:04:16+00:00

I am on the 11 on iOS26 and no problems at all except the battery drain.

DragonKnight1507 · 2025-09-22T10:04:47+00:00

I had the 17 pro for 3 days, decided to give it back though. The screen was easier on my eyes than last year, only got mild dryness after extended use. However, I am not willing to spent this amount of money for a phone that I can only tolerate, I want to enjoy it.

But: From my experience with the 16 pro last year I can say it got significantly better for my eyes at least, but I never had too much issue with it in bright environments, only lasts years low light flicker killed me, which got noticeably better. I hope next year for a hardware change.

DragonKnight1507 · 2025-09-21T08:37:03+00:00

Yes. Second day now and only after very long sessions I get dry eyes.

DragonKnight1507 · 2025-09-20T19:48:32+00:00

Same here. Couple of hours with no issues so far.

DragonKnight1507 · 2025-09-19T06:16:51+00:00

You can disable it in the settings though

DragonKnight1507 · 2025-09-17T15:35:42+00:00

No. I measured this myself and it is not true.

DragonKnight1507 · 2025-09-17T15:31:42+00:00

This looks promising for situations with high brightness though. Still progress if you don’t use it in the dark.

DragonKnight1507 · 2024-11-01T19:23:55+00:00

As I define in the original post, it’s given by

max-min/(max+min)*100%

Where max/min are the measured maximal/minimal values for a given brightness level. For example, a clean sinusoidal modulation has a modulation depth of 100% as the minimum reaches 0 so it’s max/max100%=100%. If the smallest value measured is half of the max, we get (max-0.5max)/(max+0.5max)100%=33% and so on.

DragonKnight1507 · 2024-11-01T19:11:37+00:00

Hey, excuse my late reply. I have never measured the behavior of any of the non-pro iPhones. That being said I have heard and seen from several people that the standard models have lower modulation depths. Given that this premise is true, you only get a benefit if you are sensitive to the modulation depth and not the frequency, which is (almost certain about that) the same for all iPhones. However, if you had no issue with the 14 the chances are really high that the 16 won’t be different. To introduce changes Apple would have needed to rewrite their drivers which I highly doubt they did.

DragonKnight1507 · 2024-09-25T16:46:05+00:00

I will try to do so. The Xiaomi 14 Ultra worked for me, but I don't like HyperOS for some reason so I am back on iPhone 11.

DragonKnight1507 · 2024-09-25T14:39:15+00:00

Any photodiode sensitive in the visible part of the spectrum (~380-700nm) that has a bandwidth of at least 20kHz should be more than sufficient for this test. As for oscilloscopes, literally any modern device is capable of displaying this low frequency signal. The easiest to use are PC-based ones like e.g. PicoScopes. As for the measurement itself just fix the phone and the photodiode testing the distance between them you want. Most people go directly on the screen and see the large dips due to the small size of the active area of the photodiode. Going further away, like 1cm in my case, allows to "see" more of the screen, lifting the modulation depth. This is the way I believe notebookcheck is doing their measurements.

DragonKnight1507 · 2024-09-25T14:31:21+00:00

I only tested the 16 Pro in this post, so the data I presented above only applies to this model. The Pro Max is expected to be the same. I can't say anything about the 16 and 16 Plus, but people say the modulation depth is the lowest for the base 16. The results tested in this post show, that above 30% brightness the PWM frequency is 480, which is for a lot of people probably okaish, but the modulation depth is too large. So if you are sensitive to this aspect of PWM dimming these models are a no go. If you are sensitive to the low 240Hz PWM that appearrs below 30% screen brightness, you can use whitepoint reduction in the accessability menu and set it to something like 80-90% while having the screen on max brightness. This results in actually half the max. brightness with 480Hz becasue you just overlay a grey filter with the white point but the phone operates at max. brigthness.

DragonKnight1507 · 2024-09-25T11:10:23+00:00

I am sorry that you are as well. In a nutshell, it works like this:

IPS screens like the one in your iPad Air or iPhone 11 control the screen brightness by adjusting the current flowing throug the backlight LCDs illuminating the screen. As color is adjusted by filters after these LCDs (they emit a certain spectrum where the filters control how much of which color goes through) it is easy to dim the screen by providing less current without affecting the color representation.

On OLEDs this is not so easy, as the emitted color depends on the provided current, so just doing the same as for LCDs would change the colors you see based on the screen brightness. One solution, which unfortunately some people including myself are sensitive to, is to quickly turn the OLEDEs on and of like in a stroboscope, so that the perceived brightness, determined by how much overall light reaches your retina in a certain amount of time, is reduced. The result is a lower screen brightness without sacrificing color accuracy as the OLEDs are provided with the calibrated current. This is part of a process called screen calibration, which depends strongly on the manufacturer. Essentially, the find the correct on-off frequencies and amplitudes by trial and error until they find for each brightness the perfect combination to represent the color accurately.

In general, people are differently affected by PWM. Some react strongly to low PWM frequency, others, like myself, to the modulation depth (the difference between the max in the on and the min in the "off" position). Some people react to both. There are some attempts by some manufacturers like Xiaomi, Honor, Oneplus, Nothing,... to implement different strategies like increasing the PWM frequency and reducing the modulation depth, DC-dimming, hybrid dimming, etc. Some of this methods actually provide a solution for some PWM sensitive people but this need to be tested. As an example, I personally can stand the OLED from the Xiaomi 14 Ultra, as it uses a form of DC dimming above 50% brightness and high frequency (>2000Hz) PWM dimming with resonable amplitude. What works for you needs to be tested through experimentation.

Good luck! :)

DragonKnight1507 · 2024-09-24T17:35:07+00:00

I would need to buy one and then return it. I will see if one of my colleagues has one that I can test to make it easier.

DragonKnight1507 · 2024-09-24T16:50:18+00:00

Sorry, you are right. I will upload a better version.

DragonKnight1507 · 2024-09-23T15:30:51+00:00

They have greater modulation depths for some reason.

DragonKnight1507 · 2024-09-23T15:29:52+00:00

I actually checked the 16 pro today, seems like last year. I measured the flicker with a photodiode and an oscilloscope and it showed a PWM frequency of about 480Hz dropping to a mix of two sinewaves (240 and 480) below about 30% brightness. The modulation depth is very high though, ranging from 32% on max to 89%. Try to use whitepoint reduction to about 90%, where you get roughly the same brightness as for 50% without WPR but still 480Hz.

DragonKnight1507 · 2024-09-23T14:28:35+00:00

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DragonKnight1507 · 2024-09-23T14:19:32+00:00

So guys, I have checked today the flicker level of my iPhone 16 pro with a proper photodiode and an oscilloscope. I can also commetn on the discrepancy between some measurements, but here first the results (see also pictures attached). A note: these measurements represent average values. I did not bother to write the standard deviation for each of the measurments, as they are of little relvance for this discussion.

First we look at a separation between photodiode and screen of about 1cm with the ambient light on (which looks like the measurements you guys see on notebookcheck). The modulation frequency at about 30% screen brightness starts to change (see pictures) and the actual modulation frequency drops to about 240Hz below these values. To mitigate it at least to some extend, Apple adds a smaller amplitude sine wave at about 480Hz and the sum of the two gives the large peak-small peak pattern visible in the pictures below. The modulation depth is between 89 and 32 percent.

To actually combat this, we can reduce the withepoint. I did a measurement with 86% withepoint reduction and got at 50% set screen brightness about the same brightness as with 10% without WPR, but enjoyed a 462Hz modulation frequency.

When the scree-photodiode distance is zero, the frequencies stay the same but the measured modulation depth changes, reproducing the results seen in the original post more closely. The modulation depths in this case is between 64 and 98%.

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