US 3,549,241 A — Ikuo Mori
| 11 ELEMENTS / 9 GROUPS |
| f ≈ 20.0 mm |
| F/4 |
| 2ω = 90° (PATENT) |
| ALL-SPHERICAL |
Patent close-range correction: the air gap inside the split L5 component closes from 0.432 to 0.314 mm at 1/25× magnification while the image distance grows. The near image distance is calculated from that published state, and intermediate positions are a linear interpolation. The production lens focuses to 0.30 m, which the patent does not tabulate.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | 620603 — dense barium crown, SK16 class (J-SK16 HIKARI / S-BSM16 OHARA coordinate-compatible; supplier unconfirmed) |
| L2 | Negative Meniscus | 697556 — lanthanum crown, LaK14 class (J-LAK14 HIKARI / S-LAL14 OHARA coordinate-compatible; supplier unconfirmed) |
| L3 | Negative Meniscus | 697556 — lanthanum crown, LaK14 class (J-LAK14 HIKARI / S-LAL14 OHARA coordinate-compatible; supplier unconfirmed) |
| L4a | Negative Meniscus | 678555 — lanthanum crown, LaK12 class (LAC12 HOYA / K-LaK12 SUMITA coordinate-compatible; supplier unconfirmed) |
| L4b | Biconvex Positive | 606439 — barium flint, BaF4 class (S-BAM4 OHARA / N-BAF4 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L5a | Plano-Convex | 603380 — flint, F5 class (J-F5 HIKARI / F5 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L5b | Plano-Convex | 603380 — flint, F5 class (J-F5 HIKARI / F5 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L6a | Biconcave Negative | 762265 — dense flint, SF14 class (J-SF14 HIKARI / S-TIH14 OHARA coordinate-compatible; supplier unconfirmed) |
| L6b | Positive Meniscus | 767462 — lanthanum dense flint (nearest J-LASFH2 HIKARI, nd identical, catalog νd 46.78, Δνd +0.58; supplier unconfirmed) |
| L7 | Positive Meniscus | 517642 — borosilicate crown, BK7 class (J-BK7A HIKARI / N-BK7 SCHOTT coordinate-compatible; supplier unconfirmed) |
| L8 | Positive Meniscus | 639450 — barium flint, BaF12 class (BAF12 SUMITA / S-BAM12 OHARA coordinate-compatible; supplier unconfirmed) |