DE 2818435 B1 — Optische Werke G. Rodenstock
| 6 elements / 4 groups |
| f ≈ 79.95 mm (d-line) |
| f/4; stops to f/22 |
| 6×9 cm enlarging coverage |
| 4–15× recommended scale range |
Finite-conjugate enlarging lens; focus is set by changing enlarger lens/negative/easel distances. The optical unit is rigid and the patent publishes no internal focus variables.
| Element | Type | Glass |
|---|---|---|
| L1 | Plano-Convex Positive | N-LAK9 (Schott) |
| L2 | Plano-Concave Negative | N-KZFS4 (Schott; KzFS4 class) |
| L3 | Positive Meniscus | N-SK16 (Schott) |
| L4 | Positive Meniscus | N-SK16 (Schott) |
| L5 | Plano-Concave Negative | N-KZFS4 (Schott; KzFS4 class) |
| L6 | Plano-Convex Positive | N-SK16 (Schott) |
Detailed analysis available in the interactive viewer above.