US 3,589,798 — Toshinobu Ogura
| MINOLTA: 11 ELEMENTS / 8 GROUPS INCLUDING BUILT-IN FILTER |
| ACTIVE MODEL: 10 ELEMENTS / 7 GROUPS |
| 16mm f/2.8 |
| 180° DIAGONAL FISHEYE |
| MINIMUM FOCUS 0.3m |
NO_INTERNAL_RECONSTRUCTION — Minolta specifies 0.3 m minimum focus, but US 3,589,798 Example II publishes no focus-spacing or movement table; the model remains at the published infinity prescription.
| Element | Type | Glass |
|---|---|---|
| G1 | Negative Meniscus, convex to object | 620603 — SK16/BSM16/BACD16 class |
| G2 | Negative Meniscus, convex to object | K-SSK1 (SUMITA catalog equivalent; patent 618527; production supplier unspecified) |
| G3 | Biconcave Negative | 620603 — SK16/BSM16/BACD16 class (melt/rounding residual) |
| G4 | Biconvex Positive | H-LaF4 (CDGM catalog equivalent; patent 750349; production supplier unspecified) |
| G5 | Plano-Convex Positive | Unmatched (733282 dense flint; no compatible public coefficient row) |
| G7 | Positive Meniscus, convex to image | N-SK16 / S-BSM16 / J-SK16 catalog-equivalent crown class (patent 621612; supplier unspecified) |
| G8 | Negative Meniscus, convex to image | Unmatched (733282 dense flint; no compatible public coefficient row) |
| G9 | Biconcave Negative | Unmatched (740375 high-index flint; no compatible public coefficient row) |
| G10 | Biconvex Positive | 569560 — BAK4/BAC4/BaK7 class |
| G11 | Biconvex Positive | 517642 — BK7/BSC7/K9L class |