DE 1,089,991 — Pennig / Rodenstock
| 4 ELEMENTS / 3 GROUPS |
| f = 50.0 mm |
| f/2.8 |
| 2ω ≈ 47.2° |
| 0 ASPHERICAL SURFACES |
Unit focusing as an enlarger objective; the patent publishes no internal variable air gaps.
| Element | Type | Glass |
|---|---|---|
| L1 | Near-Plano-Convex Positive | LaK12 class (678/555; LAC12 / H-LaK5A / K-LaK12 equivalents) |
| L2 | Biconcave Negative | F7 class (625/356; Schott F7 / CDGM F6 equivalents) |
| L3 | Near-Plano-Concave Negative | Schott FL2 class (589/410; historical) |
| L4 | Biconvex Positive | LAF3 class (717/479; S-LAM3 / H-LaF2 / K-LaF3 equivalents) |
Detailed analysis available in the interactive viewer above.