US 4,806,000 — Yoshiharu Shiokama, Naoto Ohta, Hiroshi Okano, Kiyotaka Inadome
| 15 elements / 11 groups |
| computed f = 28.833-83.289 mm |
| production f/3.5-4.5; patent f/3.5-4.0 |
| all spherical |
| patent macro state beta = -0.25 at wide end |
Normal focusing is by front-group G1 translation. The tabulated close-focus state models the patent macro setting at the wide end: G1, G2, and G4 move together toward the object while G3 and the stop remain fixed.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-FSL5 (OHARA) |
| L2 | Negative Meniscus | S-LAM3 (OHARA) |
| L3 | Biconcave Negative | 797455 - TAF2 class (Hoya legacy; no exact catalog match) |
| L4 | Positive Meniscus | S-TIH6 class (OHARA) |
| L5 | Positive Meniscus | J-SFH2 (Hikari; 861231) |
| L6 | Negative Meniscus | J-SFH2 (Hikari; 861231) |
| L7 | Biconvex Positive | S-FSL5 (OHARA) |
| L8 | Negative Meniscus | E-FL5 equivalent (legacy LF5 class) |
| L9 | Plano-Convex Positive | S-BSM14 (OHARA) |
| L10 | Positive Meniscus | S-TIH11 class (OHARA) |
| L11 | Biconcave Negative | S-BSL7 / N-BK7 class |
| L12 | Biconcave Negative | BALK3 (SUMITA catalog equivalent for patent coordinate; production supplier unspecified) |
| L13 | Plano-Convex Positive | SK5 type (589/612) |
| L14 | Biconvex Positive | S-BSM10 (OHARA) |
| L15 | Negative Meniscus | 795287 - J-LAFH3 (Hikari; no source-backed catalog match) |