US 2,745,315 Example 1 — Brendel / Agfa
| 6 ELEMENTS / 4 GROUPS |
| f ≈ 50.08 mm |
| F/2 |
| 2ω ≈ 46.7° |
| ALL-SPHERICAL |
Unit focus; final back-focus gap varies from infinity to a representative 0.914 m (3 ft) close-focus setting; this finite state is not patent-published.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | N-SK15 / SK15 class (Schott; patent 623/581) |
| L2 | Plano-Convex Positive | S-BAH11 (Ohara) / BaF11 cross-reference class (patent 667/484) |
| L3 | Plano-Concave Negative | Unmatched (625/356 flint; CDGM F6/H-F6 and Schott F7 class candidates) |
| L4 | Concave-Plano Negative | Unmatched (625/356 flint; CDGM F6/H-F6 and Schott F7 class candidates) |
| L5 | Plano-Convex Positive | S-BAH11 (Ohara) / BaF11 cross-reference class (patent 667/484) |
| L6 | Biconvex Positive | N-SK15 / SK15 class (Schott; patent 623/581) |
Detailed analysis available in the interactive viewer above.