US 4,708,445 — Hisashi Goto
| 9 ELEMENTS / 7 GROUPS |
| f ≈ 50.0 mm |
| F/2.0 |
| 2ω ≈ 45.6° |
| ALL SPHERICAL |
Floating element: entire lens advances while the air gap between Group I (L1+L2) and Group II (L3+L4) increases, maintaining aberration correction from infinity to 1:2 magnification.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | F5 (603/380) |
| L2 | Biconvex Positive | S-LAL18 (OHARA; 729/547) |
| L3 | Positive Meniscus | N-LAF34 (Schott catalog-equivalent to patent 773497; supplier not identified) |
| L4 | Negative Meniscus | PBL25 (OHARA, 581408) |
| L5 | Biconcave Negative | BAF22 (HOYA catalog-equivalent; production supplier unspecified) |
| L6 | Biconvex Positive | S-LAM61 (OHARA, 720460) |
| L7 | Positive Meniscus | N-LAF34 (Schott catalog-equivalent to patent 773497; supplier not identified) |
| L8 | Biconvex Positive | N-LAF34 (Schott catalog-equivalent to patent 773497; supplier not identified) |
| L9 | Negative Meniscus | SF4 (755/275) |