How to darken the four corners of a photo when shooting with a SLR?

Ordinary SLR cameras cannot be set to "corner darkening".

From the lens point of view, if a wide-angle lens uses a long hood or multiple filters are superimposed, dark corners will appear.

Most people who want to get photos with dark corners want to simulate the "LOMO" style, and this effect can be produced in the post-processing software of pictures. For example, the domestic post-processing software "Light and Shadow Magic Hand" has the option of generating LOMO-style photos with one click. Please see the following screenshot for the processing method in this software:

Figure 1, the "digital darkroom" menu of the light and shadow magician has LOMO style options (shown by the red arrow).

Figure 2, the picture effect after selecting LOMO style.