About iOS/iPadOS Auto-Brightness
iOS/iPadOS devices use an ambient light sensor to adjust brightness levels based on the light conditions around the device, lowering brightness in dark locations and raising brightness in light locations. Auto-Brightness is a system feature and current behavior may change with updates to iOS/iPadOS.
While Auto-Brightness is enabled by default, it can be disabled on the device:
- in iOS/iPadOS 13, 14, & 15, go to Settings > Accessibility > Display & Text Size > Auto-Brightness.
- in iOS 11 & 12, go to Settings > General > Accessibility > Display Accommodations > Auto-Brightness.
- in iOS 10 and earlier, go to Settings > Display & Brightness > Auto-Brightness.
Auto-Brightness is automatically disabled within Kiosk Pro if Control Active Brightness Level is enabled.
If Control Active Brightness Level is disabled and the system Auto-Brightness toggle is turned on, the screen will remain at a set brightness level until:
- the brightness is changed manually in Control Center
- Auto-Brightness is turned off and back on
- the screen is turned off and back on
- a change in ambient light level is detected
One exception to the above appears to be that changes in ambient light levels do not trigger a change if the brightness is set to maximum (100%).
If the device is inside an enclosure that covers the light sensors, that would prevent the final condition from triggering at lower percentages as long as the brightness was set after the device was installed in the enclosure.