What does horizontal asymmetric defocusing mean?

Horizontal asymmetric defocusing refers to the phenomenon that the focus position in the horizontal direction is uneven or not accurately aligned during the imaging process. In general, the focus should be kept in the center of the object during the imaging process, so that the object can present clear outline and details on the image. However, if there is horizontal asymmetric defocus, the image may be blurred, distorted or tilted.

Horizontal asymmetric defocusing may be caused by many factors, including equipment problems, improper focal length adjustment, lens or sensor damage, etc. Specific analysis may require inspection of the equipment and further adjustment or maintenance. I suggest you contact a professional photographer or camera repairman to solve this problem.