US 4,260,223 A, Embodiment 1 — Yoshinari Hamanishi
| 6 ELEMENTS / 5 GROUPS |
| 55mm |
| f/2.8 |
| 43° |
| 0.25m / 1:2 |
CONSTRAINED_RECONSTRUCTION to the production 1:2 endpoint at 0.25 m. The patent's d6 is split at the published diaphragm: STO→7 remains 3.199900 mm, while 6→STO changes 4.115650→5.574172 mm. The BF change 42.456380→69.922557 mm is the lens-relative equivalent of both groups moving objectward against a fixed film plane.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | 773494 — M-TAF1 (HOYA) coordinate-compatible spectral proxy; production supplier unresolved |
| L2 | Positive Meniscus | 713539 — lanthanum-crown coordinate class (supplier unresolved) |
| L3 | Negative Meniscus | 613369 — F3 (SUMITA) coordinate-compatible spectral proxy; production supplier unresolved |
| L4a | Biconcave Negative | 699300 — dense-flint coordinate class (supplier unresolved) |
| L4b | Biconvex Positive | 744494 — M-NBF1 (HOYA) coordinate-compatible spectral proxy; production supplier unresolved |
| L5 | Biconvex Positive | 797454 — J-LASF017 (HIKARI) coordinate-compatible spectral proxy; production supplier unresolved |