US 3,874,770 A — Yoshiyuki Shimizu
| 6 ELEMENTS / 6 GROUPS |
| MODELED EFL 35.001 mm |
| F/2.8 |
| 62° FIELD |
| ALL-SPHERICAL |
Infinity prescription only. The patent publishes no focusing data, so no focus movement is modelled and no minimum focus distance is specified.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 515546 — crown flint, KF3 class (KF3 SUMITA coordinate-compatible; supplier unconfirmed) |
| L2 | Positive Meniscus | 517642 — borosilicate crown, BK7 class (J-BK7A HIKARI / N-BK7 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L3 | Biconvex Positive | 713539 — lanthanum crown, LaK8 class (J-LAK8 HIKARI / LAC8 HOYA coordinate-compatible; supplier unconfirmed) |
| L4 | Biconcave Negative | 717295 — dense flint, SF1 class (J-SF1 HIKARI / SF1 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L5 | Positive Meniscus | 744494 — lanthanum flint (nearest NBF1 HOYA / S-LAM60 OHARA, Δnd −0.0011; supplier unconfirmed) |
| L6 | Biconvex Positive | 620603 — dense barium crown, SK16 class (J-SK16 HIKARI / S-BSM16 OHARA coordinate-compatible; supplier unconfirmed) |