US 3,804,494 Example 1 — Olympus / Keiichi Ito
| 6 elements / 5 groups |
| f ≈ 200.02 mm |
| F/5 |
| 2ω = 12°10′ |
| All-spherical |
Unit focus. The patent publishes only the infinity prescription; the close-focus BFD is estimated from the 2.5 m production MFD.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-FSL5 (OHARA) |
| L2 | Negative Meniscus | S-TIH10 (OHARA) |
| L3 | Positive Meniscus | K10 (Schott) |
| L4 | Plano-Concave Negative | S-LAM2 (OHARA) |
| L5 | Negative Meniscus | S-LAL8 (OHARA) |
| L6 | Biconvex Positive | S-FTM16 (OHARA) |
Detailed analysis available in the interactive viewer above.