Fig. 1. Principles for focal length calculation utilizing ray tracing

Fig. 2. Definitions for local focal length.

Fig. 3. Optical layouts of fisheye lens with 160° FOVs utilizing LFL raytracing and controlling

Fig. 4. Curves of targeted LFL and designed LFL for fisheye lens with 160°FOVs for the design configurations

Fig. 5. Grid distortions for fisheye lens with 160° FOVs for the design configurations

Fig. 6. Mapping relationships for curved object

Fig. 7. Ideal mapping relationships for curved object utilizing wide angle lens with 120° FOVs

Fig. 8. Optical layouts of wide angel lens with 120° FOVs for curved object with equal arc length mapping

Fig. 9. Designed result of wide angel lens with 120° FOVs for curved object with equal arc length mapping