DE 1 228 820 B — Hans Lautenbacher / Enna-Werk
| 7 elements / 7 groups |
| f ≈ 24.0 mm |
| f/4 |
| 2ω = 85° |
| all spherical |
Unit focusing. The patent gives only the infinity prescription; close focus is modeled by increasing BFD for a 0.25 m object distance.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | N-BK7 (Schott) |
| L2 | Negative Meniscus | N-SK16 (Schott) |
| L3 | Positive Meniscus | F7-class flint (legacy Schott 625/356; CDGM H-F6 equivalent) |
| L4 | Biconvex Positive | K4-class crown (legacy 519/573) |
| L5 | Positive Meniscus | BaF8-class barium flint (legacy 624/470) |
| L6 | Biconcave Negative | SF56A (Schott) |
| L7 | Biconvex Positive | H-BaF6 (CDGM) / barium-flint 608/462 class |
Detailed analysis available in the interactive viewer above.