What's the name of the shadow in Android camera?

Shadow is called lens dark corner in Android camera, which is caused by large aperture in most cases. The word dark corner belongs to photographic terminology. Facing the scene with uniform brightness, the four corners of the picture darken, which is called loss of light, commonly known as dark corner. Dark corners in photography are inevitable for any lens.

The main reasons for the dark corner are that the angle between the imaging light at the corner and the optical axis of the lens is large, the brightness at the corner is low, and the color filter is used too much.