Is there a way to set the brightness/luminance of a Mac built-in display via actual numerical values? either by entering a number or a slider with a scale with markings, say "120cd/m2" for example? I can do it in my colorimeter's software, but if I need to change it then it's guess work with Apple's sliders in Displays or on a keyboard. I've seen Terminal commands to do so, but it's like "key code -.5" etc, so relative. I would guess that the system doesn't have an actual "real" scale like the colorimeter, but I'd settle for something that at least gave me a set point around say the 120cd/m2 I set with the meter, sort of like a bookmark.