Auto brightness is fundamentally changed with the latest versions of iOS and this means that if you just drag the brightness slider in Control Center on your iPhone up and down, you will only temporarily adjust brightness, but it will not stay fixed and will keep on adjusting to the environment.

So... how can you get a full manual control over screen brightness on the latest iPhone XS, XS Max and XR?

You can do it in a few simple steps, but keep in mind that Apple has made it harder simply because auto-brightness works very well and your average user will not need to have this manual control in the daily grind. If you do, however, here is how to take a full manual control over screen brightness.