US 2,645,974 — Hiroshi Ito
| 6 ELEMENTS / 4 GROUPS |
| f ≈ 28.0 mm |
| F/3.5 |
| 2ω = 75° |
| ALL SPHERICAL |
Unit focusing — entire lens moves as rigid unit.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-BAL41 (OHARA catalog equivalent; production supplier unspecified) |
| L2 | Biconvex Positive | E-BAF8 (HOYA) |
| L3 | Biconcave Negative | E-F8 (HOYA catalog equivalent for patent coordinate; production supplier unspecified) |
| L4 | Biconcave Negative | FL4 (HOYA catalog equivalent; production supplier unspecified; patent 579417) |
| L5 | Biconvex Positive | N-SK16 (Schott) |
| L6 | Plano-Convex Positive | N-SK16 (Schott) |