US 3,915,558, Example 8 — Erhard Glatzel
| 9 ELEMENTS / 8 GROUPS |
| f ≈ 36.5 mm |
| F/1.4 |
| 2ω ≈ 62° |
| 1 ASPHERICAL SURFACE |
Calculated unit focus: the whole lens extends 7.08 mm for 0.3 m. The patent gives infinity data only; the production floating close-range correction is not modeled.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | BAF3 catalog equivalent (583/465 barium-flint class; J-BAF3 spectral row; production supplier unspecified) |
| L2 | Negative Meniscus | LLF1 catalog equivalent (Schott 548/458; production supplier unspecified) |
| L3a | Biconvex Positive | N-LAK8 catalog equivalent (historical LaK8 family; production supplier unspecified) |
| L3b | Positive Meniscus | N-LAK8 catalog equivalent (historical LaK8 family; production supplier unspecified) |
| L4 | Positive Meniscus | N-LAK8 catalog equivalent (historical LaK8 family; production supplier unspecified) |
| L5 | Biconcave Negative (1× Asph) | LLF1 catalog equivalent (Schott 548/458; production supplier unspecified) |
| L6 | Biconcave Negative | SF57 catalog equivalent (Schott 847/238 class; production supplier unspecified) |
| L7 | Biconvex Positive | N-LAF21 catalog equivalent (historical LaF21 788/474 family; production supplier unspecified) |
| L8 | Biconvex Positive | N-LAF21 catalog equivalent (historical LaF21 788/474 family; production supplier unspecified) |