US 7,508,592 B2 Example 2 — Hiroki Harada / Nikon
| 24-70mm f/2.8 marketed; f=24.78-67.70mm, FNO=2.91 design |
| 15 elements / 11 groups production count |
| 16 modeled optical media including replicated resin asphere layer |
| 3 ED elements, 3 aspherical surfaces |
| Internal focus: G2a moves imageward |
Internal focus by imageward movement of G2a (hybrid asphere L4 plus L5/L6 cemented doublet); close-focus spacings are paraxial estimates because the patent gives infinity data only.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus (1x Asph) | 744495 — unmatched high-index lanthanum-crown class (patent nd=1.744429, νd=49.52; no exact public catalog match) |
| L2 | Biconcave Negative | S-PHM52 (OHARA) |
| L3 | Positive Meniscus | S-TIH53 (OHARA) |
| L4r | Thin Positive Meniscus (Asph) | 553381 — unmatched UV-cure replicated resin (patent nd=1.55389, νd=38.09; not catalog glass) |
| L4g | Biconvex Positive | S-LAH66 (OHARA) |
| L5 | Negative Meniscus | S-TIH14 (OHARA) |
| L6 | Biconvex Positive ED | J-FKH1 (HIKARI) |
| L7 | Biconvex Positive | S-LAH58 (OHARA) |
| L8 | Positive Meniscus | S-TIH53 (OHARA) |
| L9 | Biconcave Negative | S-LAL18 (OHARA) |
| L10 | Negative Meniscus | S-LAL18 (OHARA) |
| L11 | Negative Meniscus | S-TIH6 (OHARA) |
| L12 | Biconvex Positive ED | J-FKH1 (HIKARI) |
| L13 | Biconvex Positive (1x Asph) | S-BSL7 (OHARA) |
| L14 | Positive Meniscus ED | J-FKH1 (HIKARI) |
| L15 | Negative Meniscus | S-TIH6 (OHARA) |
Detailed analysis available in the interactive viewer above.