What's the difference between autofocus and non-autofocus for mobile phone photos? Does it have a big impact?

The clearest image can be obtained when the focus is accurate, that is, when the subject is on the focal plane. Generally, the lens has a certain depth of field, that is, the scenery within a certain distance before and after the focal plane can be clearly imaged, which is called defocus imaging. The factors that affect the depth of field are: aperture opening, focal length and object distance.

Auto-focus mobile phones can generally focus automatically and accurately, so the image is clear.

The mobile phone without auto-focus function has a large depth of field by properly setting the parameters that affect the depth of field, and can get a clear image in most cases.