US 4,210,388 EXAMPLE 1 — OLYMPUS / Y. IKEDA
| 11 ELEMENTS / 9 GROUPS |
| f ≈ 21 mm (marketed) / 28.5 mm (computed) |
| F/2.0 |
| 2ω = 92° |
| ALL SPHERICAL |
Unit focus (BFD only). Production lens uses floating elements — not modeled here.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | LAC14 / BaLF5 (OHARA / Schott) |
| L2 | Negative Meniscus | LAC10 / LaK9 (OHARA / Schott) |
| L3 | Negative Meniscus | LAC12 / LaK10 (OHARA / Schott) |
| L4a | Plano-Convex | F2 / TIF1 (Schott / OHARA) |
| L4b | Plano-Convex | F2 / TIF1 (Schott / OHARA) |
| L5 | Negative Meniscus | LAC7 / LaK8 (OHARA / Schott) |
| L6 | Biconvex Positive | LF7 (Schott) |
| L7 | Positive Meniscus | LaF3 / LAF2 (Schott / HOYA) |
| L8 | Biconcave Negative | SF57 (Schott) |
| L9 | Biconvex Positive | LaK21 / LAC11 (Schott / HOYA) |
| L10 | Negative Meniscus | LaK14 / LAC9 (Schott / HOYA) |
Detailed analysis available in the interactive viewer above.