1. Color difference

2. Ball difference

3. Huicha
Huicha is a monochromatic difference of points outside the axis. When an off-axis object point is imaged with a large aperture beam, the emitted beam passes through a lens and no longer intersects at any point, resulting in a point like image of a single light spot, resembling a comet, hence the name "Huixia".

4. Astigmatism
Astigmatism is also an off-axis point monochromatic phase difference that affects clarity. When the field of view is large, the object points on the edge are far away from the optical axis, and the beam tilt is large, causing astigmatism after passing through the lens. Astigmatism causes the original object point to become two separate and perpendicular short lines after imaging, which combine on the ideal image plane to form an elliptical spot. Astigmatism is eliminated through complex lens combinations.

5. Field tune

6. Distortion