JP S39-10178 B, sole example — Jiro Mukai
| 7 ELEMENTS / 5 GROUPS |
| DESIGN f = 50.00 mm |
| DESIGN F/0.95 |
| ALL SPHERICAL |
Whole-lens helicoid focusing to 1 m. Only the back-focus distance changes; the close-focus position is calculated from the infinity prescription.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-LAH52 (OHARA coordinate equivalent; supplier unconfirmed) |
| L2 | Positive Meniscus | BAF10 (HOYA coordinate equivalent; supplier unconfirmed) |
| L3 | Biconvex Positive | LAC13 (HOYA coordinate equivalent; supplier unconfirmed) |
| L4 | Biconcave Negative | E-FD4 (HOYA coordinate equivalent; supplier unconfirmed) |
| L5 | Biconcave Negative | FF5 (HOYA coordinate equivalent; supplier unconfirmed) |
| L6 | Biconvex Positive | S-LAH51 (OHARA coordinate equivalent; supplier unconfirmed) |
| L7 | Biconvex Positive | S-LAH51 (OHARA coordinate equivalent; supplier unconfirmed) |