As some who unknowingly had PWM sensitivity for years and now realizing what it was, I've been on a warpath to experiment with not only the new iPad Pro OLEDS but my current range of iPhones, MacBook, Apple Display, etc. I would call my sensitivity moderate as it seems I can tolerate some semblance of 500Hz and above based on my testing. Massive shoutout to Notebookcheck (NBC) for their results and graphs, couldn't have narrowed it down without them!
What is PWM:
A very rapid frequency of on/off states of the digital signal to achieve a result similar to what could be achieved on a plain Analog signal. If you wanted 70% screen brightness for example, you would simply need to keep the digital signal on for 70% of the time and off for 30% of the time your screen was turned on. This is done rapidly, with the frequency measured in Hertz (Hz), or number of times per second. The faster the frequency, the less noticeable the off states become, until the resulting effect is indistinguishable from what an analog signal would produce. (https://www.notebookcheck.net/Why-Pulse-Width-Modulation-PWM-is-such-a-headache.270240.0.html)
My Symptoms:
It always started with some type of vertigo/spacey feeling almost like motion sickness after about 5min of just starring at the screen followed by nausea with migraines. I originally thought it was the higher refresh rate so I limited that but it didn't do much outside of a placebo effect for the first few minutes. I also experimented with dark/light modes & reduced white point but knowing it's a frequency issue this was just a hypothesis that understandably didn't work.
iPad Pro 13":
The worst case scenario is 240HZ which just destroyed me. I checked NBC and the highest freq was at 100% brightness barely reaching 480Hz. I cranked up the brightness to 100% and set reduce white point to 100% as the level is unbearable and while it worked to alleviate most of my symptoms I knew that using a device like this wasn't sustainable. Reducing white point has nothing to do with brightness so my screen on time would take a massive hit as well. Ultimately not worth it so the 13" was out of the running. (https://www.notebookcheck.net/Apple...st-only-superlatives.863481.0.html#11602264-5)
iPad Pro 11":
You would think the frequency compared to the 13" would be the same but they are vastly different. While the worst frequency is 240Hz just like the 13" the frequency of the 11" at 50% brightness is 550Hz! Oddly at 75% it goes back to 240HZ and at 100% it's 480Hz so not only does 50% brightness achieve the highest frequency, which is what we want, but it's much more manageable to the battery life and viewing when using reduce white point on/off. After a couple of days just lounging inside the house my symptoms have been greatly reduced except for maybe long hours of exposure but longer sessions are need. (https://www.notebookcheck.net/Apple...r-and-lightning-fast.842302.0.html#11357191-5)
iPhone 13 Pro:
I used this as my control. Compared to the iPhone 13 Pro Max, the regular 13 Pro has 510Hz and utilizes DC dimming so it takes me a very long time to get symptoms from the phone if at all. Due to DC dimming I am able to utilize the auto brightness feature as the flickering stays consistent throughout all brightness ranges. Additionally, the iPhone 13 Mini I used for years is 510Hz but the moment I bought a 13 Pro Max I would have the same symptoms as above and never knew why until I look back now and see it was a 240Hz freq. (https://www.notebookcheck.net/Apple...martphone-with-minor-weaknesses.572211.0.html)
Apple Display/MacBook Air/MacBook Pro (miniLED):
No issues either due to lack of PWM overall (LCD) or in the case of the miniLED the freq is into the thousands so it's not noticeable to me.
Overall:
Using Siri to ask for 50% brightness on my IPP 11" was beneficial since you can't determine the exact level utilizing the brightness slider. My iPad Pro 11" is still treating me well at 50% brightness and so is my iPhone Pro 13. For me it looks like anything over 500Hz is good for long periods but in order to utilize auto brightness I need DC dimming, super high freq, or no PWM at all. Hope this helps someone else and love to hear your experiments.
What is PWM:
A very rapid frequency of on/off states of the digital signal to achieve a result similar to what could be achieved on a plain Analog signal. If you wanted 70% screen brightness for example, you would simply need to keep the digital signal on for 70% of the time and off for 30% of the time your screen was turned on. This is done rapidly, with the frequency measured in Hertz (Hz), or number of times per second. The faster the frequency, the less noticeable the off states become, until the resulting effect is indistinguishable from what an analog signal would produce. (https://www.notebookcheck.net/Why-Pulse-Width-Modulation-PWM-is-such-a-headache.270240.0.html)
My Symptoms:
It always started with some type of vertigo/spacey feeling almost like motion sickness after about 5min of just starring at the screen followed by nausea with migraines. I originally thought it was the higher refresh rate so I limited that but it didn't do much outside of a placebo effect for the first few minutes. I also experimented with dark/light modes & reduced white point but knowing it's a frequency issue this was just a hypothesis that understandably didn't work.
iPad Pro 13":
The worst case scenario is 240HZ which just destroyed me. I checked NBC and the highest freq was at 100% brightness barely reaching 480Hz. I cranked up the brightness to 100% and set reduce white point to 100% as the level is unbearable and while it worked to alleviate most of my symptoms I knew that using a device like this wasn't sustainable. Reducing white point has nothing to do with brightness so my screen on time would take a massive hit as well. Ultimately not worth it so the 13" was out of the running. (https://www.notebookcheck.net/Apple...st-only-superlatives.863481.0.html#11602264-5)
iPad Pro 11":
You would think the frequency compared to the 13" would be the same but they are vastly different. While the worst frequency is 240Hz just like the 13" the frequency of the 11" at 50% brightness is 550Hz! Oddly at 75% it goes back to 240HZ and at 100% it's 480Hz so not only does 50% brightness achieve the highest frequency, which is what we want, but it's much more manageable to the battery life and viewing when using reduce white point on/off. After a couple of days just lounging inside the house my symptoms have been greatly reduced except for maybe long hours of exposure but longer sessions are need. (https://www.notebookcheck.net/Apple...r-and-lightning-fast.842302.0.html#11357191-5)
iPhone 13 Pro:
I used this as my control. Compared to the iPhone 13 Pro Max, the regular 13 Pro has 510Hz and utilizes DC dimming so it takes me a very long time to get symptoms from the phone if at all. Due to DC dimming I am able to utilize the auto brightness feature as the flickering stays consistent throughout all brightness ranges. Additionally, the iPhone 13 Mini I used for years is 510Hz but the moment I bought a 13 Pro Max I would have the same symptoms as above and never knew why until I look back now and see it was a 240Hz freq. (https://www.notebookcheck.net/Apple...martphone-with-minor-weaknesses.572211.0.html)
Apple Display/MacBook Air/MacBook Pro (miniLED):
No issues either due to lack of PWM overall (LCD) or in the case of the miniLED the freq is into the thousands so it's not noticeable to me.
Overall:
Using Siri to ask for 50% brightness on my IPP 11" was beneficial since you can't determine the exact level utilizing the brightness slider. My iPad Pro 11" is still treating me well at 50% brightness and so is my iPhone Pro 13. For me it looks like anything over 500Hz is good for long periods but in order to utilize auto brightness I need DC dimming, super high freq, or no PWM at all. Hope this helps someone else and love to hear your experiments.
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