US 7,898,744 B2 — Mitsuaki Wada
| 12 ELEMENTS / 9 GROUPS |
| f ≈ 58.0 mm (patent) / 60 mm (marketed) |
| F/2.88 |
| EXAMPLE 2 — UNSCALED |
| 2 ASPHERICAL SURFACES |
| LOW-DISPERSION L7 (vd = 82.56) |
Internal floating focus: G2 moves toward image, G3 moves toward object. G1, G4, and aperture stop fixed. Source stations: infinity, half-size (inferred 0.229 m), life-size (inferred 0.177 m). Track about 124.2 mm; source middle station differs by 0.00137 mm. G2 travel: 11.2 mm, G3 travel: 21.4 mm.
| Element | Type | Glass |
|---|---|---|
| L1 | Neg. Meniscus (1× Asph) | S-LAH63Q (OHARA, inferred coordinate counterpart) |
| L2 | Positive Meniscus | K-SK18 (Sumita, inferred coordinate counterpart) |
| L3 | Biconvex Positive | TAFD5 (HOYA, inferred coordinate counterpart) |
| L4 | Neg. Meniscus (1× Asph) | S-BSL7 (OHARA, approximate coordinate counterpart) |
| L5 | Biconcave Negative | S-TIM2 (OHARA, inferred coordinate counterpart) |
| L6 | Biconvex Positive | S-LAH58 (OHARA, inferred coordinate counterpart) |
| L7 | Biconvex Positive | J-FKH1 (Hikari, inferred coordinate counterpart) |
| L8 | Biconvex Positive | S-PHM53 (OHARA, inferred coordinate counterpart) |
| L9 | Negative Meniscus | S-TIH53 (OHARA, inferred coordinate counterpart) |
| L10 | Negative Meniscus | S-TIH6 (OHARA, inferred coordinate counterpart) |
| L11 | Negative Meniscus | J-LAF016 (Hikari, inferred coordinate counterpart) |
| L12 | Positive Meniscus | S-TIH53 (OHARA, inferred coordinate counterpart) |