MacOS 10.15.1 - After installing, every time I reboot my iMac my screen is set to the maximum brightness. I can adjust it in system preferences, but I have my screen calibrated to a specific brightness for photography. I have "Automatically Set Screen Brightness" UNCHECKED so it shouldn't make any changes. Any ideas how to keep the brightness set where I had it when I shut down.
iMac Line (2012 and Later)
After turning off Night Shift, the brightness was not raised when I opened my Macbook in the morning for a couple of mornings, but this morning it was back to max (or maybe close to max - a bit hard to tell as I opened the brightness slider on the Touch Bar and kept my finger on the button so may have slid the level down slightly). But it had definitely risen by itself. :-/
Same issue with a external monitor. When the macOS wake up, the internal screen brightness light up with previous brightness, then one or two seconds later, the external screen detected by system, all the screen flash and both of them starting work, but the internal screen becomes the max brightness.
My mac model is iMac 5k 2019
UPDATE from my post. The last two updates did not address this issue. As stated in my original post the auto brightness is off and night shift is off. I do have a second monitor connected via USB to HDMI and have had this set up that worked well prior to Catalina. Now it appears that after start up the iMac screen starts at full bright. I again adjust it in settings to a lower level. If I unplug the second monitor and plug it back into the iMac the iMac returns to full brightness. This is a problem as I am a photographer and calibrate the monitors for editing.
I see exactly this happening on macbook pro as well, when more than one display is connected. I'm not able to reproduce the behaviour when there are no external displays connected.
Don't recall if this is from 10.15.1 or later updates.
It is super annoying, specially in evenings :(
Neither the resetting SMC nor the power procedure fixes the problem for me. It should be noted that I have a USB expander on my two left USB-C ports that gives me the HDMI port needed for the external display. I assume this is affecting timing of the Mac discovering the external display. Still no excuse for that screwing up brightness setting when NO auto-adjust brightness is enabled.
Same here. I have an iMac and it's been very annoying issue since I upgraded to Catalina. I'm a photographer so all my monitors are calibrated. I have to reset the brightness after a restart or when the imac wakes up from sleep. I've tried resetting the memory, pulled out the power cord etc. Toggled the power nap in energy saver, on, off.
Any other solutions or this a major issue waiting for a Apple fix?
Got the same issue after updating to Catalina 10.15.1 on MacBook Pro (13-inch, 2016, Four Thunderbolt 3 Ports).
Same problem. Every time my Mac wakes, it is at full brightness. Auto brightness change is disabled. EXTREMELY annoying as I work in a darkened room.
Same issue after Catalina 10.15.1 update
- MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports)
Night Shift has been off for quite sometime.
Sadly , the 10.15.2 software update made available last week did not fix the issue on my machine.
Still no known fix?
Yes, bug still exists... And it seems no public solutions yet.
Go to Energy Saver, unselect "Power Nap while on battery power". This might work.
iMac doesn't have a setting for battery😂
And my MBP16 works well on external monitor. It's strange.
Thanks but I don't use the option to automatically adjust the brightness. I have noticed just now that the brightness issue only happens when I have additional monitors plugged in.
macos 10.15.1 boots with screen at full brightness
