Good screen on Intel Macbook Pro became bad after plugging into HDMI

devilgrove

I'm currently using a Macbook Pro 2020 (Intel) running Catalina, and had success over the last couple of years using the nvram boot-args="dither=0" method. Recently, I wanted to try plugging it in to an external monitor to see how my eyes would react, so I bought an Anker USB-C hub to test it out. Unfortunately, not only was the external monitor bad for my eyes, but the internal display (which used to be good) somehow also turned bad for my eyes. I'm getting the visual snow on the default Catalina background that I didn't get before. Any leads on how this happened / how I could fix this?

DisplaysShouldNotBeTVs

devilgrove sometimes plugging in monitors can cause Intel MacBooks to change from 8bit to 10bit color depth even after disconnecting. that happened on a 2018 MBA I tested. is the internal display still set to 8bit in betterdisplay?

also surprised that dither=0 worked on your Mac. it didn't work at all for me on both a 2016 MBP 13" and a 2018 MBA.

the only devices I've gotten it to work on are 2015 and earlier. the only Mac it truly "significantly improved" for me is the 2015 12" single-port MacBook

(The way I prove it is that shifts in banding should show up while changing color table software brightness in betterdisplay after successfully disabling dithering. It's "smooth" instead when the boot arg isn't there. On the devices it did not work on, adjusting the color table remained smooth even after setting the boot arg)

async

Would be nice with some reliable technique to clear out all screen config so it is easier to test things. Even clearing old stored EDIDs and screen config seemed almost impossible in Sonoma. I have some usb c ports that won't even work with some external monitors after all the experimentation. Deleting the lists or clearing the values doesn't work anymore.