US 2,927,506, Example 1 — Fritz Determann
| 6 ELEMENTS / 5 GROUPS |
| 35mm f/3.4 |
| 63° DIAGONAL (MARKETED) |
| DKL / BESSAMATIC |
| ALL-SPHERICAL |
The patent provides only an infinity prescription; the documented 0.99 m minimum focus distance is not modeled.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 501565 — K10-class crown (vendor not established by patent) |
| L2 | Positive Meniscus | 664359 — BASF2-class dense barium flint (vendor not established by patent) |
| L3 | Biconvex Positive | 624470 — BAF8-class barium flint (vendor not established by patent) |
| L4 | Biconcave Negative | 607402 — BAFD3 compatible spectral proxy; patent vendor unspecified |
| L5 | Negative Meniscus | 617366 — F4/PBM4-class flint (vendor not established by patent) |
| L6 | Biconvex Positive | 691548 — LAK9-class lanthanum crown (vendor not established by patent) |