US 4,457,596, Embodiment 1 — Koichi Wakamiya
| 5 ELEMENTS / 4 GROUPS |
| f ≈ 35.0 mm |
| F/2.8 |
| 2ω ≈ 62.3° |
| ALL SPHERICAL |
Unit focus — entire lens translates forward; calculated extension 1.69 mm at 0.8 m (patent gives infinity data only).
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | J-LAK8 (HIKARI catalog equivalent to patent 1.713/54.0; production supplier unspecified) |
| L2 | Positive Meniscus | S-LAH66 (OHARA catalog equivalent, nearest 773/496 row; patent 1.77279/49.4 has no exact catalog match) |
| L3 | Biconcave Negative | S-TIM28 (OHARA catalog equivalent; exact 689311 coordinate match, production supplier unspecified) |
| L4 | Biconvex Positive | S-LAH66 (OHARA catalog equivalent, nearest 773/496 row; patent 1.77279/49.4 has no exact catalog match) |
| L5 | Negative Meniscus | N-SK16 (Schott catalog equivalent to patent 1.62041/60.4; production supplier unspecified) |