US 5,530,593, Embodiment 1 — Atsushi Shibayama, Susumu Sato
| 12 ELEMENTS / 10 GROUPS |
| DESIGN f = 39-102 mm |
| DESIGN F/4.08-8.05 |
| ALL SPHERICAL |
The patent favors moving G3 toward the image to focus but prints no close state, so this model holds infinity focus at every zoom position and no group moves with focus. The 0.75 m closest distance rests on a single hobby reference page.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconcave Negative | E-LAFH2 (HIKARI catalog equivalent; production supplier unspecified) |
| L2 | Biconvex Positive | K-SSK1 (SUMITA catalog equivalent; production supplier unspecified) |
| L3 | Positive Meniscus | J-SK16 (HIKARI catalog equivalent; production supplier unspecified) |
| L4 | Biconcave Negative | TAF3D (HOYA catalog equivalent; production supplier unspecified) |
| L5 | Biconvex Positive | FD3 (HOYA catalog equivalent; production supplier unspecified) |
| L6 | Positive Meniscus | N-BK7 (Schott catalog equivalent; production supplier unspecified) |
| L7 | Positive Meniscus | J-PKH1 (HIKARI catalog equivalent; production supplier unspecified) |
| L8 | Negative Meniscus | J-SFH2 (HIKARI catalog equivalent; production supplier unspecified) |
| L9 | Biconvex Positive | J-PKH1 (HIKARI catalog equivalent; production supplier unspecified) |
| L10 | Positive Meniscus | SF4 (Schott catalog equivalent; production supplier unspecified) |
| L11 | Negative Meniscus | Unmatched (840433 lanthanum flint; no public catalog row) |
| L12 | Negative Meniscus | S-LAL14 (OHARA catalog equivalent; production supplier unspecified) |