Classification of defocus imaging

Out-of-focus imaging can be divided into two types:

1, fuzzy:

In addition to the focus, the whole picture is blurred and there is no residual part at the edge, which is the best defocus imaging;

2. Bilinear ambiguity:

This is not an ideal defocus imaging, and the outline of the defocus picture of the subject is separated by two lines or several lines. The most obvious example is the catadioptric lens, which has obvious bilinear. Bilinear appearance easily interferes with the subject visually.