Why is "auto adjust brightness" washing out my retina display on El Capitan? When I check and uncheck this System Preference "Automatically adjust brightness", my display gets slightly washed out instead of brighter or darker. It seems to be adjusting the gamma and the grays instead of the backlight brightness.

What's going on here and is it possible to restore the behavior of Yosemite and earlier with this option?



A sample of the gamma difference with setting enabled/disabled.
It is a new feature called ‘Ambient light compensation’. Before the Beta 7 or so it was a separate option in that menu on your screenshots, but in newer betas and in the finale release Apple merged it with the ‘Automatically adjust brightness’ checkbox, so yes, it is now adjusting not only backlight brightness, but gamma as well.

The only solution I found so far is to turn off that checkbox and adjust backlight brightness manually, which isn't a solution really. Hope Apple will bring back a separate checkbox for ambient light compensation.