The photo format also affects the resolution of the photos. on the Oppo smartphone, the format can be changed between 1:1, 4:3, 16:9 and Full. how high the resolution of the photos is then depends on the model.

Android 10 | ColorOS 7.0
Step 1:  Open the  Camera -App
Step 2:  Open the  Menu
Step 3:  Tap on  Frame
  1. Open the Camera-App
  2. Open the Menu
  3. Tap on Frame

Oppo Instructions