Easy way to turn off Auto Brightness on iOS 15

If you are using an Apple device running iOS 15 (iPhone, iPod, or iPads), you would notice that the brightness of the device is auto-adjusted based on the environmental fluctuations in lighting (the auto-brightness feature is on by default for any new device you purchase).

If you do not want the device to automatically increase or decrease the brightness of your iOS device you can turn it off by going to the Settings App -> Accesiblity -> Display & Test Size, Scroll down and turn off "Auto-Brightness"

iOS 15 Truning Off Auto-Brightness Setting.

Note: As you can see in the sub-text below the Auto-Brightness button in the above screenshot, turning off auto-brightness may affect the battery life and long-term display performance.

iOS devices contain the ambient light sensor using which the device can adjust the brightness levels of the device based on the light conditions around you, if you are in outside bright sunlight you would see that the screen brightness is auto-adjusted to high levels, so does the sensor lowers the brightness when you are in a dark place - say using the phone in your bed while the lights are turned off, at night.

When auto-brightness is turned off, you'll notice that the brightness slider on your device does not move according to changing light conditions.

✌️The battery life of your iOS device would vary significantly based on how you set the brightness of your device - read more on - https://support.apple.com/en-in/HT202613#brightness