I'm testing as many MacBooks as possible. Here are the results.

Btw I think it would interest everyone to say I am actually using the new Dasung Paperlike Color and I've been working on my non symptomatic MBP all morning, having just switched to the symptomatic one I can see the general overall image is way different I need to find time to post this and take photographs of the differences I'm seeing.

@macsforme my comfortable MPB has Bootrom: 1037.147.4.0.0 | iBridge 17.16.16610.0.0.0

uncomfortable identical MBP: Bottom 1968.100.17.0.0 (iBridge: 20.16.4252.0.0,0)

I spoke to someone at Apple and gave up in the end but he was saying that was the only difference in the machine aside from the fact that my comfortable one was bought in the UK and uncomfortable one turns out to be a US Machine.

GBowler Thank you! So the GPU information in the system profile is identical between the two? That info seems to be the most pertinent. I know display panels can come from different vendors as well, which could certainly be a factor (although I don’t know of a way to identify the panel manufacturer on modern Macs).

GBowler Then just omit --process 0

and enter such command after rebooting your laptop:

log show -last 15m | grep ahkinject

NewDwarf thankyou!! I have no clue about these Terminal commands

Yes I got a long read out very similar to the one you shared! so it has worked thank you!!!

There seems to be something other than dithering going on that is giving me symptoms (this is all connecting to a 10bit Eizo monitor btw)

Really appreciate your help and it is good to know that dithering may not be the sole thing I need to focus on!!

macsforme Yes I've just checked and the Graphics/Displays details are identical between the two!

And I'm going into an Eizo 10bit external monitor

So it seems to be this Bootrom, I spoke to a guy who was advertising on eBay and he said he could replace the chip, is it the EFI chip? and that I just needed to give him the firmware version, I think it was around £300 so I think I may try that as an experiment.

On a total tangent I'm finding the Dasung Paperlike Color to be super helpful, tough going to get used to but I managed a half day video editing on it this morning!!

GBowler My understanding is that for Macs up until around 2017 (where I am focusing my research), the firmware/ROM is on a ROM chip which is accessible for read/write using a diagnostic port on the motherboard and a special cable and programmer. So, you can dump the ROM, extract the necessary parts and inject them into an older ROM update file (from Apple), then flash that back to the motherboard. I have done this a few times. Notably, the main firmware/ROM is only one component of several which can be updated, but this is where I have focused so far.

For later Macs, my understanding is that BridgeOS runs on the T2 chip, and like an iOS device you can only flash an older BridgeOS while Apple is still signing it (so only recent versions). I believe the firmware/ROM resides on the main SSD with the OS and user data, but the NAND flash is encrypted by the T2 so I do not see how you can manipulate it (other than perhaps erasing the entire NAND flash chips). You can use Apple Configurator 2 to "revive" or "restore" the firmware and operating system, but again, only recent versions still signed by Apple. So, I am curious if this person can actually flash an older firmware version on a T2 Mac, and whether that includes the BridgeOS.

GBowler Do you check on the external monitor? The problem is the external screen can be PWM enabled.

NewDwarf I haven't read much about PWM at all compared to dithering, so potentially these two MBP could be sending different pwm frequency to the monitor?

Lauda89 When you took the measurements with your Opple LightMaster, did you test the same color for both devices? I'm guessing you tested a brighter color (like white) for the Macbook and a dimmer color (like gray) for the gaming PC.

It would be best to use the same colors for both. And also to try using a handful of different colors, comparing the same color on one device with the same color on the other device.

Here's a handy page that lists all 256 shades of gray, red, green and blue. Obviously you don't need to test all 1000+ colors, but testing 20 different colors might produce interesting results. https://pixelinversion.com/AllColors.html

Also, it would be interesting to see the waveform from your iPhone X. 99.5% modulation depth is pretty crazy for a screen.

macsforme

I can absolutely confirm this. MacOS Ventura update from 13.2.1 to 13.3 changed something on firmware level of my M2 MBP 13". I was able to use it for hours, but it added some high frequency flickering that's best seen with white text on black background. It's completely unusable now. I can see this flickering even I take my eyes off the screen, it takes maybe 15-30 minutes to get my sight in order after using it.

What’s worse that is seems to be irreversible. I downgraded to earlier Ventura and even Monterey. I went to service and asked them to downgrade the firmware to 13.2.1 which they did (it could be done with recovery from another mac) but nothing changed.

DigDeal To clarify, you actually downgraded the firmware, not just the operating system (macOS) version? Downgrading the firmware involves putting your Mac in DFU mode, connecting it to another Mac via USB-C/Thunderbolt, and restoring a specific macOS version using an .ipsw file using Apple Configurator 2. If only a recovery USB stick with an earlier macOS version was used, this would not downgrade the firmware. It sounds like you described an actual firmware downgrade, but I just want to be sure. I am also curious if you observed a firmware version change in the System Information app after the downgrade.

For the record, an Apple silicon MacBook Pro was where all of my vision problems started as well. There is definitely something harsh going on there.

macsforme Hi, yes, that is exactly what they did. I read an article on mrmacintosh.com about downgrading firmware to a specific version, downloaded 13.2.1 ipsw file and brought all this to a service center, where they uploaded the entire image using another Mac. As a result both "system firmware" and "OS loader" reported by system information matched the ones for Ventura 13.2.1.

NewDwarf

I finally was able to execute on a 2019 MBP 16-inch w/ Intel and AMD Radeon Pro 5600M. I got the below from terminal (the Intel response a lot longer than your above). It seems like dithering is disabled on both, right?

My eyes are a bit tired from messing with so hard to tell right now on symptoms, but…

For the AMD:

And for the Intel:

NewDwarf

As maybe a bad sign I ran this command and got the below. A lot of "unable to find any matching services." Could it be the 16" and/or AMD Radeon Pro 5600M is too new for the kernel?

Unfortunately I am still having symptoms on the 2019 MBP (and no symptoms still on my 2015 15" MBP).

Link I'm starting to wonder has my brain trained to a specific flicker or dithering pattern and others are now uncomfortable

Lauda89 That is very interesting. Here's a few ideas/questions:

1. The flicker rate on your iPhone X is 250 hz (it flickers every 4 ms), which is well above the level that most people will get headaches. So maybe you're not sensitive to OLED flicker or any kind of flickering at high speeds (say, 100 hz or higher).

2. So if you ignore the huge dips and just focus on the top line of the graphs, you'll see a correlation between headaches and the variability of the graphs. Note that when comparing these graphs, you have to keep in mind that they have different scales for the Y axis, so you have to imagine what the graphs would look like if they had the same scale.

   
   

   Iphone X (no headaches, pretty flat if you imagine what the graph would look like if the Y axis went up to 250 and not just 100.)

   

   
   

   Macbook (no headaches, pretty flat)

   

   
   

   Gaming pc (headaches, pretty ragged)

   

3. I find it really interesting that the output from your Macbook and gaming PC have different brightness levels and that the gaming PC has a more ragged line than the Macbook. I would start looking for differences in how the display works. I think you'd mentioned that one of them connects via HDMI and the other via DisplayPort. That could be worth experimenting with. But also you could look in the monitor settings (are these devices somehow using different monitor settings?). And also for the graphics card you could play around with different settings like make sure you turn off "eye care" and blue light filters and things like that. The good news is you can make various changes and test them immediately with your light meter.

4. Testing with other colors, especially light gray and light green could be interesting. Something called pixel inversion happens at 30 hz and many monitors flicker worst with light colors vs pure white.