Imaging performance optimization methods for semiconductor wafer inspection

Inspection systems and methods for adjusting/optimizing imaging performances of the inspection systems are disclosed. An inspection system may include an optical component configured to deliver inspection light to a subject and a detector configured to obtain an image of the subject at least partially based on the inspection light delivered to the subject. The inspection system may also include a processor in communication with the optical component and the detector. The processor may be configured to: measure an aberration of the optical component based on the image of the subject obtained by the detector; and adjust the optical component to compensate for a change in the aberration.