US 3,850,509 Example 1 — Olympus / Nakagawa
| 11 ELEMENTS / 8 GROUPS |
| f ≈ 16.0 mm |
| F/3.5 |
| 2ω = 180° |
| ALL SPHERICAL |
Unit focus (whole-block helicoid). No floating elements identified in patent or production literature.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | S-BAL35 (OHARA) |
| L2 | Positive Meniscus | S-LAH51 (OHARA) |
| L3 | Negative Meniscus | S-BAL35 (OHARA) |
| L4a | Negative Meniscus | S-LAL14 (OHARA) |
| L4b | Positive Meniscus | S-TIM35 (OHARA) |
| L5a | Negative Meniscus | S-TIH11 (OHARA) |
| L5b | Biconvex Positive | S-TIM5 (OHARA) |
| L6 | Positive Meniscus | 517696 — S-APL1 / APL1-class low-index high-Abbe crown (OHARA; no public Sellmeier match) |
| L7a | Negative Meniscus | S-TIH6 (OHARA) |
| L7b | Biconvex Positive | 517696 — S-APL1 / APL1-class low-index high-Abbe crown (OHARA; no public Sellmeier match) |
Detailed analysis available in the interactive viewer above.