US 2021/0033835 A1 — Makoto Nakahara
| 16 ELEMENTS / 11 GROUPS |
| 4 UD-CLASS ELEMENTS |
| PATENT f = 72.27–193.89 mm |
| PATENT F/4.08–4.12 |
| MFD 0.6 m (product) |
| 9-BLADE DIAPHRAGM |
NO_INTERNAL_RECONSTRUCTION: Example 1 publishes infinity zoom spacings and focus directions only. L4 focuses objectward and L6 imageward, but no numerical close-focus gap table is published; the data therefore models only the published infinity zoom states. Canon's 0.6 m MFD and dual Nano USM focus/floating mechanism are product metadata, not reconstructed spacings.
| Element | Type | Glass |
|---|---|---|
| L11 | Positive Meniscus | 487702 — low-dispersion crown class (vendor unresolved) |
| L12 | Negative Meniscus | 613443 — medium-dispersion class (vendor unresolved) |
| L13 | Positive Meniscus | 497815 — UD-class low-dispersion glass (vendor unresolved) |
| L21 | Negative Meniscus | 516641 — crown class (vendor unresolved) |
| L22 | Biconcave Negative | 541472 — flint class (vendor unresolved) |
| L23 | Positive Meniscus | 001255 — high-index flint class (vendor unresolved) |
| L31 | Biconvex Positive | 497815 — UD-class low-dispersion glass (vendor unresolved) |
| L41 | Biconcave Negative | 764485 — lanthanum-crown class (vendor unresolved) |
| L42 | Biconvex Positive | NBFD13 (HOYA) |
| L51 | Negative Meniscus | 051269 — very-high-index flint class (vendor unresolved) |
| L52 | Biconvex Positive | 497815 — UD-class low-dispersion glass (vendor unresolved) |
| L53 | Biconvex Positive | 835427 — lanthanum class (vendor unresolved) |
| L61 | Biconcave Negative | 835427 — lanthanum class (vendor unresolved) |
| L62 | Positive Meniscus | 728285 — dense-flint class (vendor unresolved) |
| L71 | Negative Meniscus | 497815 — UD-class low-dispersion glass (vendor unresolved) |
| L72 | Biconvex Positive | 855248 — high-index flint class (vendor unresolved) |