US 3,506,336 — Yasuo Takahashi
| 8 ELEMENTS / 7 GROUPS |
| f = 35.000 mm |
| f/2 |
| ANGLE OF VIEW 62° |
| ALL-SPHERICAL |
Unit-focus model: the complete optical assembly translates. The patent supplies only infinity data; close focus is paraxially derived for the manufacturer-specified 0.40 m MFD.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | S-BAL35 (OHARA current counterpart; Δνd = -0.06; historical melt unconfirmed) |
| L2 | Positive Meniscus | S-LAM55 (OHARA current counterpart; Δνd = -0.20; historical melt unconfirmed) |
| L3 | Biconvex Positive | S-LAH66 (OHARA current counterpart; Δnd = -0.00002, Δνd ≈ 0.00; historical melt unconfirmed) |
| L4 | Positive Meniscus | S-TIL6 (OHARA current counterpart; Δνd = -0.06; historical melt unconfirmed) |
| L5 | Biconcave Negative | S-TIH13 (OHARA current counterpart; Δνd = +0.09; historical melt unconfirmed) |
| L6 | Negative Meniscus | S-LAH60V (OHARA current counterpart; Δνd = +0.01; historical melt unconfirmed) |
| L7 | Biconvex Positive | S-LAH66 (OHARA current counterpart; Δnd = -0.00002, Δνd ≈ 0.00; historical melt unconfirmed) |
| L8 | Positive Meniscus | S-LAH66 (OHARA current counterpart; Δnd = -0.00002, Δνd ≈ 0.00; historical melt unconfirmed) |