US 2,518,719 Example 2 — Eastman Kodak / Max Reiss
| 4 elements / 4 groups |
| EFL 100.09 mm |
| f/6.3 |
| All-spherical |
| 4x5 format model |
Unit-focus model. Patent gives infinity data only; close focus is represented by BFD extension.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | N-SK16 (Schott, nearest modern catalog equivalent) |
| L2 | Negative Meniscus | F2 (Schott, nearest modern catalog equivalent) |
| L3 | Negative Meniscus | F5 (Schott, nearest modern catalog equivalent) |
| L4 | Positive Meniscus | N-SK16 (Schott, nearest modern catalog equivalent) |
Detailed analysis available in the interactive viewer above.