I’m all about hyperbole, but that’s a bit ridiculous.
That said, I have my doubts about prevailing wisdom being true here.
I can also imagine that lower frequency PWM dimming can be more problematic on a display that covers a larger portion of your sight. Many people also probably use their laptop/computer screen for a longer time without looking away (aside from phone addicts).
I'm one of the ones who is very sensitive to this. I get occular migraines often. It has become fairly difficult to find displays that don't have these problems as everyone moves to PWM dimming on everything. Even lightbulbs are a difficult purchase for the same reason (at least Ikea makes some that have zero flicker and are cheap).
I also had one, for probably 6 years or so, and never experienced this.
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.
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.
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 miss how amusement parks looked at night when I was a kid, all bathed in warm, colorful glowing lights. They are still bathed in warm colorful lights, but half of them now have shitty PWM.
In fact there is research being done in the retro gaming scene of using CRT-like scanline drawing to mimic what CRT's do for modern displays. This allows "blackframe like" insertion without the flicker. Only issue is you need a very high refresh rate display to take advantage of it and there aren't many of those.
Searching just gives me the same “PWM Sensitivity” webpages without any peer reviewed research.
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.
But when some new display technology is based on showing various image fragments at moments shifted in time, expecting that the eye will integrate them over time to form complete images and continuous movements, that may require higher sampling frequencies, up to 10 times higher, due to the interaction with the fast subconscious eye movements.
The study results are not surprising at all, and this is an effect that should be kept in mind by anyone who designs displays.
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 think I am pretty insensitive to this effect, though. Other than occasional seeing a bit of 60 Hz flicker out of the corner of my eye from Christmas lights, automotive LED tail lights, etc. I don't tend to notice flicker.
If you want to use PWM in an application like this you need to start at like 600hz. This is how fast the subfield drive on a plasma TV is.
I have to use incandescent lightbulbs for certain fixtures because I sometimes need a break from engineers who think they are smarter than me.
We’re no longer in the dark ages of flicker. There’s actual industry guidance: IEEE 1789. And 240Hz, at any respectable depth of modulation, does not meet the low-risk limit, let alone the no-observable-effect limit.
I am wondering whether this is actually just an amazing firmware goof: the reports seem to suggest that operating at full brightness mitigates the problem, which makes little sense for an OLED display. An OLED showing 50% (post-gamma) gray ought to drive the pixels the same way as an OLED at 50% brightness showing white. And this display supports HDR, so even 100% brightness white isn’t really 100%.
I’m wondering if a little engineering mistake snuck in: some (most?) LCD displays dim by PWM-dimming the backlight, and plenty of backlights have current-to-light transfer functions that inherently low-pass filter the light. If someone naively ported the same logic to an OLED (which doesn’t have a backlight), they might have implemented brightness controls by applying a 240Hz envelope to the pixel excitation waveform. This makes no sense at all as an actual implementation, but I can totally see an AI doing it and writing tests to validate it :)
Even if there is a genuine engineering factor that requires low frequency PWM, I bet Apple could mostly mitigate the problem by deliberately mismatching the phases. For decades, pre-LED stadium lights had rather extreme flicker at 120Hz, but it was tolerable because the overall system was engineered to roughly evenly split the lights between three electrical phases, giving an effective modulation depth near zero.
I haven’t seen one of these displays myself. I find 120Hz flicker to be extremely obvious and very very unpleasant, and if these displays really do modulate in a nasty way at 240Hz, I expect I’ll be able to see it, albeit rather less obviously than at 120Hz. Also, pretty much any modern phone can see this in slo-mo video mode :)
https://www.imec-int.com/en/articles/displays-health-patches...
Apparently brightness consistency between pixels is poor at low drive current, so designers often use a separate PWM envelope to compensate.
And there are even papers studying the choice of frequency, e.g.:
https://pubmed.ncbi.nlm.nih.gov/41411543/
Unsurprisingly, 240Hz is not actually recommended (at least that’s what I get from the abstract, and I’m not about to pay to read the rest of it).
And, in an IMO pathetic example of how the US patent world works, there are apparently patents on obvious architectures like using a fast PWM clock and then discretizing the VRR frame interval to multiples of the PWM time. I thought of this myself about 15 seconds after contemplating that VRR was a complication and then I searched for it and immediately found two patents. WTF!
> At 240Hz, the brightness fluctuation repeats 240 times per second; at 14,880Hz, it repeats almost 15,000 times per second.
Was that written for people who don't know what "Hz" means, or who don't know that 14880 is almost 15000?
Maybe they just let their rigol scope spit out 240hz, but 480hz worst case and I would actually say 960hz. I think what’s happening with the tandem oled is they both pwm at 480hz and 180 degrees out of phase giving effective 960hz when both are in use. Which appears to be most of the usable brightness.
Edit: I’m so confused.
“The PWM behavior is interesting, because we can see DC-dimming for all brightness levels. Usually, OLED panels use DC-Dimming only at higher brightness levels. The frequency is very low at 240 Hz, however, and this might be an issue for sensitive users, despite the DC-dimming. ” https://www.notebookcheck.net/Amazing-OLED-panel-Apple-MacBo...
A 240Hz wave would have a period of 4.17ms. 480Hz is 2.08ms. Much closer to the oscilloscope waveforms. And even then the waveforms are periodic, with smaller troughs at every second dip.
I wish I could see their test setup. It would be ironic if the panel was fully DC dimmed and the troughs were from another light source or something…
I’m not sure why the scope is saying 240 though. It makes me doubt my understanding :-/.
[Edit: Ah - got it! It’s measuring the frequency of the very lowest points - the ‘every second dip’]
⃰ ⃰(brightness - presumably the test setup is an LDR or something?)
Here's notebookcheck's review methodology:
https://www.notebookcheck.net/How-does-Notebookcheck-test-la...
And the sensor they use might be this one:
https://www.thorlabs.com/item/PDA100A2
That doesn't look like it's not even close to being able to focus on a single subpixel or even a single row without additional optics.
In any case, the 0% and 25% waveforms look pretty bad. In my experience, light with sharp, short pulses (like "driverless" LED lights produce) are unpleasant, but the unpleasantness is related to how bright the source is compared to everything else in the field of view. (The 0% and 25% waveforms are solidly at twice the frequency of driverless LEDs, which will make the effect considerably less bad.)
Surely someone on HN has the equipment and curiosity to double-check all this as a Sunday afternoon project?…
How can they assume the rise/fall slope in those plots is characterizing the driving electrical signal? Wouldn't a PWM driver be able to have much faster transitions and look more square than that at these time scales?
It makes me wonder if this is the response of the organic phosphors and the difference in apparent "depth" of the dip is really just a difference of duration, since the dips are very V-shaped, rather than bottoming out.
It is slightly odd that it has this paired rhythm, but I don't think you can assume it is "DC-dimming" rather than just PWM quanta that are being anti-alias filtered by the phosphors and measurement methodology.
It’s also odd to think about lack of ability to concentrate, and I wonder if screens cause this optically somehow but to a less noticeable degree even when less intense than this new one? (Independent distracting contents)
I noticed that adding a severe red filter to all my screens helped me significantly with the concussion and am also curious about that, would that impact the intensity of a refresh perhaps? Is blue light specifically the problem? I’m unsure but have a plethora of subjective experience.
I’m glad for this to enter public consciousness a bit and would love to see more research on the screen itself impacting our brain.
red/blue/green detectors (cones) in our eyes use different paths and have different "refresh rates" than luminous intensity sensors (rods), im wondering if filtering to a single color makes the rods take over for visual pattern processing
My matte MBP 2010 didn't yield me this issue, but I didn't game on it either; just watched movies/series. A lot of them.
I grew up with CRT monitors though, and these could cause severe headaches. Especially if resolution too high.
I had to return the Steam Deck OLED and LCD because their displays PWM was burning my eyes out. Sore eyes for days, having problems to focus properly. I hope this is a learning process and it will get better from the manufacturer side. But I hoped that after my personal Steam Deck fiasco as well.
https://www.youtube.com/watch?v=H43wnV-v7V0 Single OLED isn’t good enough long term. (Gamers will however claim it’s OK. 9 hours a day is 3285 hours in a year.
https://www.youtube.com/watch?v=H43wnV-v7V0 Single OLED isn’t good enough long term. (Gamers will however claim it’s OK. 9 hours a day is 3285 hours in a year.
The Gamer Boys are in denial about the inherent weaknesses of single OLED see the comment section.
It is to do with higher framerates on movies than we are used to, making movies look like cheaper filmed tv shows. Not a specific display technology working differently.
Peter Jackson famously had this issue when trying to show The Hobbit in 48fps, and that was in projectors in theaters.
Notice on the wikipedia page for 'Soap Opera Effect' it doesn't mention the term OLED once.
For example, could we overlay a software dimmer while driving the panel at max brightness?
Or would it be possible to tune PWM settings from the OS?
Or would this be possible to tune with a firmware change?
Idk how these things work.
Here are some other things that people are sensitive to: - CRI on white LEDs (and flourencents). CRI is how clean the spectrum is in comparison to the sun or a incandescent bulb, where the specturm is completely even. There are some CRI >=95 LEDs that are fine for most people however.
- Motion blur Motion blur on LCDs (such as ~50% of Nintendo Switch 2s) can hurt eyes trying to keep track of what is going on.
The only setting I recall changing on the TV is the one that stops the soap-opera effect.
Btw for anyone wondering, recent "Chinese" phones appear to do a damn good job. I have a recent BBK device, and I run eye comfort mode on 24/7, and despite being hyper sensitive to pwm (my previous oled phone was bad), this is quite comfortable.
My parents have a plasma TV and I can clearly see it flicker, although it doesn't cause any pain.
Bottom of the barrel, eye searing cool white LEDs with bad CRI and flicker control makes my life really harder. Low quality florescent bulbs also create eye strain for me.
The best solution I have found is 90CRI, dimmable Philips LED bulbs. They grow warmer as you dim them, and they create a very comfortable environment for me. Also, a big Bauhaus branch in my city uses mixed temperature LEDs to tune resulting color and temperature. Since ceilings are so high, you don't see the lamps and feels like you're walking under sunlight. It's that good, kudos to them.
Now I go purely for IPS and make sure it's flicker-free. I'm really glad the new MBP screens are an extra and not the new default yet.
The thing that makes that so insidious is that not everybody can easily perceive that.
(The reason why such flicker is common in cheap LED bulbs: they turn AC into DC using a half-wave rectifier, which just chops off half the AC wave. This is also why you can still see the effect in rooms lit by multiple lights, because the flicker is in sync, synchronized to the incoming AC.)
If you are building a space for other people and you are responsible for the lighting, please check for this. If you can't perceive it yourself, find someone who can.
Heh, this is how I test these lamps as well. Also my camera has anti-flicker shutter which can detect it to thwart it by syncing the shutter release with flicker itself. It shows a warning when it detects is, as well.
Nice! Which cameras do this? And I wonder, how cheaply could a sensor be made to do this, that shows on the screen "there's flicker at 60Hz / 120Hz / 480Hz", if it didn't also need to be a great camera (e.g. it only captured at 480p)?
However, I wouldn't say "oh that's easy", because A7-III has two realtime DSPs, and one of them is directly responsible for things like real-time focusing, face/object/eye recognition and real time tracking, etc. So, I believe that DSP is handling the flicker detection as well.
...and A7-III is the "entry level" member of its generation. higher end models have more computing power than that.
Unfortunately all those things are expensive so you rarely find such bulbs in the cheap bin at Home Depot.
Or just use your phone’s slo-mo feature to take a 240 FPS video (which then gets played back at 30 FPS). 60 Hz flicker becomes extremely visible. More than once I’ve noticed the strobe effect and then confirmed it this way.
PHILIPS LED A19 Ultra Definition Soft White Light Bulbs, 4-Pack 800 Lumen, 2700K, Dimmable, Flicker-Free, 60 W Equivalent, CRI95 True Colors, EyeComfort Technology
https://www.amazon.com/LED-Definition-Flicker-Free-Equivalen...
I also have some 75 W and 100 W equivalents, but they get pretty pricey, at least in Bezosland.
The absolutely worst were the default indoor lights in Australia. There must have been some giant shipment of worst possible lights that they purchased to light up every bathroom in the country.
This world wide transition to cheap LEDs stole a lot of joy from the world.
The only use case I can think of for this machine is testing iOS touch interactions without a physical phone. Just this one specific purpose and it's not one that would require prolonged use.
If Apple had released this exact machine without touch it would still sell just as well.
The frequency is the frequency. If you have a problem with it, it’s your bad luck because the frequency over the years has been somewhere between 30hz and 120hz thru the years depending upon the use case.
Apple still making some good products also doesn't disprove my statement.
There’s also trade off to high pwm, usually worse color accuracy. But at least give us a toggle!
My personal feud with OLEDs, is that even at very high resolution the fonts do not look as smooth and creamy as the equivalent IPS. It is like I can tell apart their subpixels.
For example I prefer text on my old iPhone 8 compared to my iPhone 17.
Another alternative, that Apple offered on their desktop screens was simply a higher resolution 5K or 6K XDR screen, which are some of the better screens you can get on a desktop computer depending upon what you are using it for, and I don’t mean to play time wasting games.
Single OLED in particular despite all its problems, is the favorite of gamers in the PC world. The previous screen, Apple offered actually is a better screen top to bottom… I prefer the 6K XDR but it and 5k despite being great screens have never been cheap. (the Internet is filled with people crying about the price most of whom thought Apple should sell it at the price of a cheap 4k screen). You got what you paid for which is a great Apple screen.
https://www.youtube.com/watch?v=H43wnV-v7V0 Single OLED isn’t good enough long term. (Gamers will however claim it’s OK. 9 hours a day is 3285 hours in a year.
Back in the CRT days, it always bugged me when a display's refresh rate was down at 60 Hz, but otherwise I think I'm not too flicker-sensitive.
[1] https://www.reddit.com/r/PWM_Sensitive/comments/1f9j3fi/pixe...
Ps the reason DC dimming isn't used so much is because at least with white LEDs the color temperature tends to change when the DC level changes so it's complicated to calibrate the screen accordingly. In particular the screen gets warmer at lower settings. This can actually be welcome because these settings will be used more at night and a lot of people prefer warmer settings then these days. But it's something that the user should be able to control.
Not sure if this applies to oled too though.
In a rigorous blinded comparison, would the new OLED MacBook cause more physical discomfort than the mini-LED model? How to explain all the symptoms being experienced?
What’s most likely?
1. Real MacBook hardware issue
2. Nocebo. Expectation of PWM problems > real physical symptoms
3. False correlation. Real headaches/eyestrain but from other causes
How surprising would it be if the answer is not (1)?
On the other hand, half rectified LED christmas lights have noticeable flicker to me and can make me feel irritable and woozy.
My question is, when it's trivial to create a PWM circuit that switches at 20khz or higher, why do manufacturers continue using anything in the 60-500hz range that people seem to notice and complain about? Do they save 2 cents or something?
I got sensitive eyes and can sense even previous gens' pwm at 15kHz. At 240Hz, I can probably see the pixels turning on and off! Only joking obviously. But I can definitely perceive the unstable luminosity. I can easily spot the OLED screens from 15ft away.
Definitely not going to upgrade. Sadly, this is most likely going to be the standard for Apple going forward.
it would be interesting to get a high speed camera and see if there's a difference in the temporal dimension as well as a careful analysis of the font rendering. it would be funny if there were some kind of metamer noise in there or something that only some people have sensitivity to.
i would also be curious if the matte display option solves it (or has solved it for anyone else).
It's interesting but unsurprising that now _more_ technical issues creep in, given that the whole idea fundamentally was flawed. If given the necessary technical scrutiny, it would not have happened. Hence, that must've been disabled. Hence other such blatant oversights like this one became much more likely, given that any voice saying "dumb idea" was already pacified.
I of course have no idea how this actually went. I am just claiming that my headcanon is canon.
I love me some high end electronics that doesn’t feel cheap but soon it will be not worth it.
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.
https://www.youtube.com/watch?v=H43wnV-v7V0 Single OLED isn’t good enough long term. (Gamers will however claim it’s OK. 9 hours a day is 3285 hours in a year.
And I don't mean gamers as in someone who plays video games but a more cultural term for a certain group of people that should be ridiculed and ostracized.
Honestly, it may be that the biggest pro of a MacBook is that it feels a world away from gamers and their constant insufferableness, creating a natural barrier.
We should quarantine gamers to windows and lock up the exit doors.
Then release Asha Sharma on them.
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?
Sometimes I can tell flickery fixtures because they just "feel more staticky". I don't get visual eyestrain or nausea though.
It's not magic. :) You DO see it. 500 Hz for the median observer; above 800 Hz for some individuals. https://doi.org/10.1038/srep07861
There is still some ability to percieve strobing at a steady state though, even if the amplitude is reduced by visual persistence.
Other than some old monochrome CRTs, all CRT phosphors decay too fast to prevent flicker. You get some softening of the trailing edges of the phantom array images, but they're not actually blurred together like on a sample-and-hold display. And even the fastest CRTs have fairly low refresh rates, making it more obvious.
what about old-timey film projection? thats ten times slower and fully on/off?
AFAIK, all OLED displays have PWM flicker, and for this reason I stick with LCD, where flicker-free displays are available (although PWM flicker is present in some LCD displays too).
https://www.notebookcheck.net/The-new-Tandem-OLED-panel-in-L...
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!
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.
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.
OLED plus dark mode is a way to juice advertised battery life.
Even if I'm not sensitive I am wary of this, what if it causes subtle eye strain that has long-term consequences?