JP1988-201614 A — Hisashi Tokumaru
| 7 ELEMENTS / 6 GROUPS |
| 35mm MARKETING / 35.0002mm MODELED |
| f/2 |
| 2ω = 64° PATENT / 63° SERVICE MANUAL |
| ALL-SPHERICAL |
| UNIT FOCUS |
CONSTRAINED_RECONSTRUCTION — rigid unit focus. The patent publishes no finite-focus spacings; the Minolta service manual states that all optical lenses translate together and gives 0.300 m MFD. The model treats 0.300 m as object-to-image-plane distance, preserves every internal spacing, and varies only BF from 36.398842615 to 42.338034718 mm (+5.939192103 mm extension).
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 532488 — extra-light-flint / TIL-class coordinate (supplier unresolved) |
| L2 | Biconvex Positive | S-LAH60 coefficient proxy (supplier unspecified; patent 834371) |
| L3a | Plano-Concave Negative | 699301 — dense-flint class coordinate (supplier unresolved) |
| L3b | Plano-Convex Positive | J-LASF016 coefficient proxy (supplier unspecified; patent 773498) |
| L4 | Biconcave Negative | 805254 — SF6-class coordinate (supplier unresolved) |
| L5 | Positive Meniscus | 786442 — lanthanum-flint class coordinate (supplier unresolved) |
| L6 | Biconvex Positive | J-LASF016 coefficient proxy (supplier unspecified; patent 773498) |