US 4,123,144 EXAMPLE 9 — MANDLER / ERNST LEITZ CANADA
| 6 ELEMENTS / 4 GROUPS |
| f ≈ 50.0 mm |
| F/2.0 |
| 2ω ≈ 45° |
| ALL SPHERICAL |
Unit focusing — entire optical cell translates forward.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | Lanthanum crown (proprietary Leitz melt; nearest: Schott TaF4 / LaFN21) |
| L2 | Plano-Convex Positive | Barium flint / dense barium crown (proprietary; nearest: Schott BaSF6) |
| L3 | Plano-Concave Negative | Dense flint (proprietary; nearest: Schott SF3 / SF10) |
| L4 | Plano-Concave Negative | Light/medium flint (proprietary; nearest: Schott F2) |
| L5 | Plano-Convex Positive | Lanthanum crown (proprietary; nearest: Schott LaF10). Same glass as L6. |
| L6 | Plano-Convex Positive | Lanthanum crown (same glass as L5) |
Detailed analysis available in the interactive viewer above.