JP 2025-162727 A, Numerical Example 1 — Daichi Tanoue
| 19 ELEMENTS / 14 GROUPS |
| DESIGN f = 194.30 mm |
| DESIGN F/2.07 |
| ALL SPHERICAL |
| 2 FLD / 2 SLD ELEMENTS |
PUBLISHED: Only G2, the single negative meniscus L8, moves, travelling 14.57 mm toward the image between infinity and the patent's 1.7 m near state, which matches Sigma's 170 cm minimum focus distance. Both end states are printed in the patent; intermediate positions are interpolated. The iris is held at its infinity size, so the patent's near-focus f/2.25 is not reproduced, and near close focus the outer drawn rays are vignetted by the first-group rims.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | FC5 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L2 | Positive Meniscus | FCD100 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L3 | Negative Meniscus | TAC8 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L4 | Positive Meniscus | FCD100 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L5 | Biconcave Negative | NBFD25 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L6 | Negative Meniscus | TAC6 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L7 | Biconvex Positive | FCD600 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L8 | Negative Meniscus | E-C3 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L9 | Biconvex Positive | NBFD30 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L10 | Biconcave Negative | S-LAH63Q (OHARA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L11 | Biconvex Positive | FDS16-W (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L12 | Biconcave Negative | LAC8 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L13 | Biconcave Negative | NBFD25 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L14 | Biconvex Positive | TAF1 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L15 | Negative Meniscus | TAFD40 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L16 | Biconvex Positive | NBFD29 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L17 | Positive Meniscus | E-FL6 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L18 | Biconcave Negative | FCD615 (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |
| L19 | Negative Meniscus | FDS16-W (HOYA; nd/νd/PgF coordinate match; production supplier unconfirmed) |