How to lower iPhone/iPad brightness?
To lower brightness lower than the limit:

Settings app &gt; General &gt; Accessibility &gt; Zoom:
Set Zoom Region &gt; &quot;Full Screen Zoom&quot;
Set Zoom Filter &gt; &quot;Low Light&quot;
Set Maximum Zoom Level all the way to the right (The highest value)

Go back to Accessibility:

Settings app &gt; General &gt; Accessibility &gt; Accessibility Shortcut:
Set &quot;Triple-Click The Home Button For&quot; &gt; Zoom

To Test: Triple click the home button and the screen will go darker.