US 3,622,227, Example I — Yoshiyuki Shimizu
| 9 ELEMENTS / 7 GROUPS |
| f ≈ 24.0 mm |
| F/2.8 |
| 2ω ≈ 84° |
| ALL SPHERICAL |
CRC: L6–L7 separation narrows, as Nikon documents. The 0.70 mm contraction is estimated; rear travel 2.92 mm is solved for a 0.30 m object-to-image endpoint. Intermediate distances are approximate.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | N-SK16 (catalog-compatible spectral proxy; patent 1.62041/60.3, catalog 1.62041/60.32; production supplier unspecified) |
| L2 | Biconvex Positive | N-SK16 (catalog-compatible spectral proxy; patent 1.62041/60.3, catalog 1.62041/60.32; production supplier unspecified) |
| L3 | Negative Meniscus | N-SK16 (catalog-compatible spectral proxy; patent 1.62041/60.3, catalog 1.62041/60.32; production supplier unspecified) |
| L4 | Biconvex Positive | F2 (catalog-compatible spectral proxy; patent 1.62004/36.3, catalog 1.62004/36.37; production supplier unspecified) |
| L5 | Negative Meniscus | E-C3 (catalog-compatible spectral proxy; patent 1.51823/59, catalog 1.51823/58.96; production supplier unspecified) |
| L6 | Biconcave Negative | S-TIH23 (catalog-compatible spectral proxy; source nd1.7847; vd26.1 inferred from L7, catalog 1.784696/26.291221; production supplier unspecified) |
| L7 | Biconcave Negative | S-TIH23 (catalog-compatible spectral proxy; patent 1.7847/26.1, catalog 1.784696/26.291221; production supplier unspecified) |
| L8 | Biconvex Positive | N-SK16 (catalog-compatible spectral proxy; patent 1.62041/60.3, catalog 1.62041/60.32; production supplier unspecified) |
| L9 | Biconvex Positive | LAF2 (catalog-compatible spectral proxy; patent 1.744/44.9, catalog 1.744/44.9; production supplier unspecified) |