How to save the original picture when taking photos with Apple's mobile phone?

Normal exposure, just turn on the camera function. Take the iPhone 7 as an example. The specific method is as follows:

First click the "Settings" icon on the phone desktop, as shown in the figure below.

2. After entering the phone setting interface, drop down the menu, and then select the "photos and cameras" option, as shown in the figure below.

3. Finally, turn on the switch in the column "Keep photos exposed normally" in the photo-camera interface, as shown in the following figure.