JPS61-77818A — Keiji Ikemori, Sadatoshi Takahashi, Takashi Matsushita, Tsunefumi Tanaka, Nozomi Kitagishi
| 15 ELEMENTS / 9 GROUPS |
| 100-300mm f/5.6 (MARKETED) |
| PATENT STATES: 69 / 100 / 198 / 290 mm |
| ALL-SPHERICAL |
| 2 m MFD (PRODUCT) |
NO_INTERNAL_RECONSTRUCTION: the patent states Group I is preferably used for focusing but publishes no close-focus spacing table. Internal geometry therefore remains at the published infinity zoom states; closeFocusM = 2.0 m is manufacturer metadata only.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | 805254 — SF6-class dense flint; vendor/melt unresolved |
| L2 | Positive Meniscus | 516641 — BSL7-class crown; OHARA S/L family unresolved |
| L3 | Biconvex Positive | 48770x — FK5/FSL5-class low-dispersion crown; source-corrected model coordinate |
| L4 | Biconcave Negative | 713538/540 — LAK8/LAL8-class lanthanum crown; vendor unresolved |
| L5 | Biconcave Negative | 697555 — LAK14-class lanthanum crown; vendor unresolved |
| L6 | Positive Meniscus | 805254 — SF6-class dense flint; vendor/melt unresolved |
| L7 | Biconvex Positive | N-KF9 coefficient proxy (patent 523508; production supplier unspecified) |
| L8 | Negative Meniscus | 805254 — SF6-class dense flint; vendor/melt unresolved |
| L9 | Biconvex Positive | 603607 — SK14/BACD14-class crown; vendor unresolved |
| L10 | Biconcave Negative | 773496 — LAF34/LAH66/TAF1-class lanthanum flint; vendor unresolved |
| L11 | Negative Meniscus | 834372/373 — LASF010/LAH60-class dense lanthanum flint; vendor unresolved |
| L12 | Positive Meniscus | BAF5-class coefficient proxy (patent 607492; production supplier unspecified) |
| L13 | Biconvex Positive | 575415 — LF7/TIL27-class light flint; vendor unresolved |
| L14 | Biconcave Negative | 804466 — LASF015/LAH65-class lanthanum flint; vendor unresolved |
| L15 | Biconvex Positive | 613370 — F3/S-TIM3-class flint; vendor unresolved |