US 2021/0026133 A1 Example 4 — Nikon
| 70-300 mm marketed; 72.1-292.1 mm patent |
| f/4.5-6.3 marketed; f/4.707-6.494 patent |
| 14 elements / 10 construction groups |
| One ED-class element; no aspherical surfaces |
| DX / APS-C image height 14.75 mm |
Internal focus by G3/L31 per patent prose; Example 4 publishes infinity zoom spacings only, so close-focus travel is not modeled in this transcription.
| Element | Type | Glass |
|---|---|---|
| L11 | Biconvex Positive | 517639 - crown glass (J-BK7 code match; patent nd=1.51680, vd=63.88) |
| L12 | Negative Meniscus | 612313 — anomalous-dispersion flint class (patent nd=1.61155, νd=31.26, θgF=0.618; no exact public catalog match) |
| L13 | Positive Meniscus | E-CF6 (Hoya) — medium-dispersion crown (517522) |
| L21 | Biconcave Negative | S-LAL14 (OHARA) — lanthanum crown (697555) |
| L22 | Positive Meniscus | J-SFH1 (Hikari) — anomalous-dispersion dense flint (808227) |
| L23 | Biconcave Negative | J-LASF021 (Hikari) — dense lanthanum flint (850324) |
| L31 | Biconvex Positive | S-BAL35 (OHARA) — barium crown (589612) |
| L41 | Biconvex Positive | J-FK01A (Hikari) — ED fluorophosphate crown (497817) |
| L42 | Biconcave Negative | J-LASF021 (Hikari) — dense lanthanum flint (850324) |
| L43 | Biconvex Positive | J-FK5 (Hikari) — low-dispersion crown (487703) |
| L44 | Positive Meniscus | J-LAF016 (Hikari) — dense flint / lanthanum-flint (801349) |
| L45 | Biconcave Negative | J-LAF01 (Hikari) — high-index flint (700481) |
| L46 | Biconvex Positive | F5 (Schott) — medium-index flint (603380) |
| L47 | Negative Meniscus | S-LAH66 (OHARA) — high-index lanthanum (773496) |
Detailed analysis available in the interactive viewer above.