US 2013/0308041 A1 — Takahiro Hatada
| 24 ELEMENTS / 19 GROUPS (PATENT ACTIVE; REAR FILTER EXCLUDED) |
| 200–400mm f/4 MARKETED |
| 205.00–389.99 mm / f/4.12 PATENT DESIGN |
| BUILT-IN 1.4× EXTENDER OUT |
NO_INTERNAL_RECONSTRUCTION: the patent publishes infinity focus only. L1 is the stated focusing unit, but no finite-distance spacing table is available; Canon's 2.0 m MFD is metadata only and focus does not alter this prescription.
| Element | Type | Glass |
|---|---|---|
| E1 | Biconvex Positive | 487702 crown class (vendor unspecified) |
| E2 | Negative Meniscus | 806333 dense-flint/lanthanum class (vendor unspecified) |
| E3 | Positive Meniscus | Fluorite (CaF2; production-correlation inference) |
| E4 | Positive Meniscus | 497816 ED/UD crown class (vendor unspecified) |
| E5 | Biconvex Positive | 904313 high-index lanthanum-flint class (vendor unspecified) |
| E6 | Biconcave Negative | 697555 lanthanum-crown class (vendor unspecified) |
| E7 | Negative Meniscus | 697555 lanthanum-crown class (vendor unspecified) |
| E8 | Positive Meniscus | 904313 high-index lanthanum-flint class (vendor unspecified) |
| E9 | Biconcave Negative | 835427 high-index lanthanum class (vendor unspecified) |
| E10 | Biconcave Negative | 835427 high-index lanthanum class (vendor unspecified) |
| E11 | Positive Meniscus | 497816 ED/UD crown class (vendor unspecified) |
| E12 | Biconvex Positive | 497816 ED/UD crown class (vendor unspecified) |
| E13 | Negative Meniscus | 904313 high-index lanthanum-flint class (vendor unspecified) |
| E14 | Positive Meniscus | 497816 ED/UD crown class (vendor unspecified) |
| E15 | Negative Meniscus | 762265 dense-flint class (vendor unspecified) |
| E16 | Biconvex Positive | 593686 low-dispersion class (vendor unspecified) |
| E17 | Biconvex Positive | 806333 dense-flint/lanthanum class (vendor unspecified) |
| E18 | Biconcave Negative | 516/517642 BK7-coordinate crown class (vendor unspecified) |
| E19 | Biconcave Negative | 652585 lanthanum-crown class (vendor unspecified) |
| E20 | Biconvex Positive | 623582 crown class (vendor unspecified) |
| E21 | Biconvex Positive | 623582 crown class (vendor unspecified) |
| E22 | Biconcave Negative | 806333 dense-flint/lanthanum class (vendor unspecified) |
| E23 | Biconvex Positive | 575415 light-flint class (vendor unspecified) |
| E24 | Biconcave Negative | 883408 high-index lanthanum class (vendor unspecified) |