If it’s as low as 240hz, anyone will see a stop motion effect by waving an open hand in front of the screen at 50% brightness.
I’m curious if this is a harmonic mode for a high speed PWM where pulses are either not even widths or the driver loses some power at the 240hz cycle. May perceive similarly.
I have a couple windows laptop workstations with high dpi OLEDs (one with 240hz refresh rate) that I love and don’t perceive this so I’ll have to check.
I am shocked that Apple would release a screen with such a low PWM frequency. Here is a paper showing humans can perceive flicker at frequencies more than double their display’s rate: https://www.nature.com/articles/srep07861
I'd be fascinated to see how common this really is. Is it something that affects .0001% of users, more, less? At Apple scale an issue like that could hit millions of people. Given the newness and expense of the product one would assume not that many OLED Macbook Pros have shipped. So it's surprising that this issue didn't come up in testing if we're talking about more than a handful of people.
Given that we discovered in the nineties that CFL tubes were unhealthy for a significant portion of the population at these refresh rates and changed to over 30kHz I would assume the same holds true here. In other words: more than we would have thought.
PWM sensitivity has been an issue on the iPhone for a long time, but the prevailing wisdom is that it affects only a small percentage of users, and then only at certain lower brightness levels. Consider it like a food allergy, we don’t rearchitect the entire food supply for everyone around the sensitivities of a few.
That said, I have my doubts about prevailing wisdom being true here.
I'd love for more research to be made into PWM sensitivity, if only to find out roughly how many people experience problems with it.
I've never had issues with it other than when trying to film certain old displays, but then again, I've never had issues with PAL TV sets running at 50 hz interlaced, nor even old PC CRTs running at 60, which definitely was not 'flicker-free', so I'm probably on the far end of the spectrum compared to the PWM sensitive.
It's an easy thing to forget, as with many accessibility features. And it's going to suck to have the nominally best display be one you just can't use if want to not feel like gouging your eyes out.
I notice PWM all around me all the time. Lots of cheaper LED lights use it, and I see it whenever I move my eyes, also when not consciously looking for it - instead of a blur I see series of lamps as a brief afterimage.
As a child I got headaches from CRT monitors at 60hz and I could see them flicker. I haven't noticed the PWM on modern monitors, but maybe these Apple ones would trigger me?
I am not particularly sensitive, but switching the ipad pro for the oled model, I just don’t like the screen that much, and it is hard to put the finger on why. Side by side, the screen has better blacks and peak brightness and I am sure it beats the LCD empirically on many metrics. But I don’t like the colors as much, and perhaps subconsciously, the flicker is turning me off.
Seriously cannot believe the PWM frequency is 240Hz. I was shocked out of my mind when I first saw that. It needs to be on the order of kHz to avoid eyestrain for a very significant proportion of the population. Did Apple just forget about accessibility, or did they underestimate it?
Slight aside. I was thinking of buying a Google Pixel 11 but I learned that they have the same problem. I will go into a store and see if the Pro version (which can do 480 Hz) is OK.
Even if I'm not sensitive I am wary of this, what if it causes subtle eye strain that has long-term consequences?
PWM frequency is not selected in a vacuum. The maximum is set by your transition time which is set by a bunch of other engineering decisions. It's possible that something about tandem OLEDs make them more difficult to drive faster edges on.
OLEDs commonly flicker at some small multiple of the refresh rate because they often use something somewhat similar to DLP bit-plane modulation to avoid non-linearity at low brightness. You can't do that at xy kHz because that would require xy kHz scanout to the panel, which is physically ... not very plausible. You can gate drive current, but then you're back to how a 2010 LED backlight operates.
TIL there’s a pretty serious downside to OLED. Love the contrast ratios but not this.
I’m not super sensitive to flicker but can be annoyed by it. I’ve used OLED phones but it’s probably not as annoying on a small screen than one that covers more of your visual field.
If you go in a dark room and set the brightness of an OLED phone to minimum and then just swing it around in front of your eyes you're very likely to see a stroboscopic effect. For iPhones this seems to become noticeable below about 20-30% brightness.
I Think Apple gets progressively worse and worse and I mean in a general way. There are some anomalies there and there but overall the direction is a slow decline in details and quality.
I love me some high end electronics that doesn’t feel cheap but soon it will be not worth it.
It’s still many times cheaper to overhaul Apple than to start another company from scratch.
They still have the right ethos, philosophy and past traditions engraved in the History of the company. Someone just needs to remind them what are they supposed to be doing.
It's not about whether you can "see 240Hz". CRT phosphors have sustain, while OLED does not. The fully-on, fully-off cycle, if infrequent enough, causes some sort of visual stimulation that some brains absolutely do not like. You don't have to see it to feel it.
Sometimes I can tell flickery fixtures because they just "feel more staticky". I don't get visual eyestrain or nausea though.
> But some people are particularly sensitive to this kind of modulation and can experience eye strain, headaches and other forms of discomfort when looking at displays that use it.
So that tiny fraction of users would be well served with some other display and can either return their MacBook or use an external monitor if and when they find out that they're in that cohort.
If it’s as low as 240hz, anyone will see a stop motion effect by waving an open hand in front of the screen at 50% brightness.
I’m curious if this is a harmonic mode for a high speed PWM where pulses are either not even widths or the driver loses some power at the 240hz cycle. May perceive similarly.
I have a couple windows laptop workstations with high dpi OLEDs (one with 240hz refresh rate) that I love and don’t perceive this so I’ll have to check.
I am shocked that Apple would release a screen with such a low PWM frequency. Here is a paper showing humans can perceive flicker at frequencies more than double their display’s rate: https://www.nature.com/articles/srep07861
I'd be fascinated to see how common this really is. Is it something that affects .0001% of users, more, less? At Apple scale an issue like that could hit millions of people. Given the newness and expense of the product one would assume not that many OLED Macbook Pros have shipped. So it's surprising that this issue didn't come up in testing if we're talking about more than a handful of people.
Given that we discovered in the nineties that CFL tubes were unhealthy for a significant portion of the population at these refresh rates and changed to over 30kHz I would assume the same holds true here. In other words: more than we would have thought.
I would say most people are actually sensitive, and report eye strain faster when using a specifc type of display, but don’t make the connection.
PWM sensitivity has been an issue on the iPhone for a long time, but the prevailing wisdom is that it affects only a small percentage of users, and then only at certain lower brightness levels. Consider it like a food allergy, we don’t rearchitect the entire food supply for everyone around the sensitivities of a few.
That said, I have my doubts about prevailing wisdom being true here.
.0001% is not nearly millions. They don’t sell billions of units
Even if they sold 100 billion units, .0001% would only be 100 thousand.
I'd love for more research to be made into PWM sensitivity, if only to find out roughly how many people experience problems with it.
I've never had issues with it other than when trying to film certain old displays, but then again, I've never had issues with PAL TV sets running at 50 hz interlaced, nor even old PC CRTs running at 60, which definitely was not 'flicker-free', so I'm probably on the far end of the spectrum compared to the PWM sensitive.
It's an easy thing to forget, as with many accessibility features. And it's going to suck to have the nominally best display be one you just can't use if want to not feel like gouging your eyes out.
I do have issues with PWM everywhere myself while CRT was not big issue. I did tinker with refresh rates though. And I think difference is that
1. CRT display phosphors had afterglow.
2. the cathode ray was a dot moving across the screen, that might be easier on eyes than whole OLED screen flashing at once.
I notice PWM all around me all the time. Lots of cheaper LED lights use it, and I see it whenever I move my eyes, also when not consciously looking for it - instead of a blur I see series of lamps as a brief afterimage.
As a child I got headaches from CRT monitors at 60hz and I could see them flicker. I haven't noticed the PWM on modern monitors, but maybe these Apple ones would trigger me?
I am not particularly sensitive, but switching the ipad pro for the oled model, I just don’t like the screen that much, and it is hard to put the finger on why. Side by side, the screen has better blacks and peak brightness and I am sure it beats the LCD empirically on many metrics. But I don’t like the colors as much, and perhaps subconsciously, the flicker is turning me off.
Seriously cannot believe the PWM frequency is 240Hz. I was shocked out of my mind when I first saw that. It needs to be on the order of kHz to avoid eyestrain for a very significant proportion of the population. Did Apple just forget about accessibility, or did they underestimate it?
Slight aside. I was thinking of buying a Google Pixel 11 but I learned that they have the same problem. I will go into a store and see if the Pro version (which can do 480 Hz) is OK.
Even if I'm not sensitive I am wary of this, what if it causes subtle eye strain that has long-term consequences?
PWM frequency is not selected in a vacuum. The maximum is set by your transition time which is set by a bunch of other engineering decisions. It's possible that something about tandem OLEDs make them more difficult to drive faster edges on.
[delayed]
> Did Apple just forget about accessibility
To this day on macOS, the font size accessibility setting only works on first-party apps!
Even when using Apple's own UI frameworks, and using semantic font sizes that do actually scale up and down on iOS / iPadOS
It astonishes me!
OLEDs commonly flicker at some small multiple of the refresh rate because they often use something somewhat similar to DLP bit-plane modulation to avoid non-linearity at low brightness. You can't do that at xy kHz because that would require xy kHz scanout to the panel, which is physically ... not very plausible. You can gate drive current, but then you're back to how a 2010 LED backlight operates.
This: https://www.notebookcheck.net/fileadmin/Notebooks/Apple/MacB... is perceptually very different from a low frequency low duty cycle PWM you'd get out of a cheap LCD backlight.
All OLED iPhones flicker below some brightness threshold, for example.
TIL there’s a pretty serious downside to OLED. Love the contrast ratios but not this.
I’m not super sensitive to flicker but can be annoyed by it. I’ve used OLED phones but it’s probably not as annoying on a small screen than one that covers more of your visual field.
If you go in a dark room and set the brightness of an OLED phone to minimum and then just swing it around in front of your eyes you're very likely to see a stroboscopic effect. For iPhones this seems to become noticeable below about 20-30% brightness.
I Think Apple gets progressively worse and worse and I mean in a general way. There are some anomalies there and there but overall the direction is a slow decline in details and quality.
I love me some high end electronics that doesn’t feel cheap but soon it will be not worth it.
They have certainly been in decline ever since Jobs died. I really hope Ternus can flip it back around.
It’s still many times cheaper to overhaul Apple than to start another company from scratch.
They still have the right ethos, philosophy and past traditions engraved in the History of the company. Someone just needs to remind them what are they supposed to be doing.
Forget, no. Liquid glass? They've abandoned accessibility.
OLED plus dark mode is a way to juice advertised battery life.
Ok but who can actually see 240hz?
Like CRTs scan slower than that, and almost no-one could say they could see the pixels being drawn.
Sure you could hear those fuckers, but not see them, unless you had a source of vibration nearby.
Howe much of this is measurable, and how much of it is similar to the Himalayan salt lamp stuff?
I can easily see at least some PWM LED headlights flickering in my peripheral vision (which is more sensitive to flicker).
Fluorescent tubes used to run at less than 100 Hz before scientists discovered that that was unhealthy for many. Now they run at 30-60 kilohertz.
It's not about whether you can "see 240Hz". CRT phosphors have sustain, while OLED does not. The fully-on, fully-off cycle, if infrequent enough, causes some sort of visual stimulation that some brains absolutely do not like. You don't have to see it to feel it.
Sometimes I can tell flickery fixtures because they just "feel more staticky". I don't get visual eyestrain or nausea though.
In my experience, Apple hardware always gets better over time. So, you should never buy the first hardware "innovation" changes that they do.
On the other hand, the first version is always the most hackable.
> But some people are particularly sensitive to this kind of modulation and can experience eye strain, headaches and other forms of discomfort when looking at displays that use it.
So that tiny fraction of users would be well served with some other display and can either return their MacBook or use an external monitor if and when they find out that they're in that cohort.