Fig. 1. Conjugate distance graph of Φ₁ and Φ₂ groups

Fig. 2. Circle radius diagram of field of view. Radius of the image plane is 12.303 mm, aspect ratio of the image plane is 4:3, length of the long side is 13.648 9 mm, and length of the wide side is 10.236 7 mm

Fig. 3. Optical scheme of a principle ray passing the negative meniscus lens

Fig. 4. Structural schematic of former-group lenses

Fig. 5. Structural schematic of rear-group lenses. the eleventh and thirteenth lenses are independent spherical lenses. The last plane is the image plane

Fig. 6. Zoom-group planning. The first group is the front zoom group, the second group is the rear zoom group, and the last plane is the image plane

Fig. 7. Optical path layout of three zoom states of the system. The first is the short-focal-length position with 8 mm system focal length, the second the medium-focal-length position with 12 mm system focal length, and the third the long-focal-length position with 16 mm system focal length

Fig. 8. MTF curves of zoom fish-eye lens system with (a) 8 mm focal length and 180° FOV angle, (b) 12 mm focal length and 120° FOV angle, and (c) 16 mm focal length and 90° FOV angle

Fig. 9. Field curvature and distortion curves for (a) short-focal-length (f=8 mm), and (b) long-focal-length (f=16 mm) positions

Fig. 10. Relative illumination curves at short-focal-length (f=8 mm) position