US 4,493,536 — Yoshinobu Kudo
| 5 ELEMENTS / 5 GROUPS |
| 28.0119 mm MODEL EFL |
| f/2.8 |
| 76° PATENT FULL FIELD |
Focus travel is not modeled: 0.3 m is production metadata only; US 4,493,536 Example 1 publishes no finite-object spacing state, so the optical model remains at the published infinity prescription.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | S-LAH64 class (coordinate-compatible spectral proxy; native d 1.78831/47.32; supplier/melt unproven) |
| L2 | Biconvex Positive | Unmatched (805445 coordinate; supplier unresolved) |
| L3 | Biconcave Negative | Unmatched (750251 coordinate; supplier unresolved) |
| L4 | Positive Meniscus | N-LAF34 class (coordinate-compatible spectral proxy; native d 1.7725/49.77; supplier/melt unproven) |
| L5 | Positive Meniscus | H-LaK12 class (coordinate-compatible spectral proxy; native d 1.6968/56.47; supplier/melt unproven) |