US 2020/0341238 A1 — Third Numerical Example
| 8 GLASS ELEMENTS / 6 GROUPS |
| f = 18.4556 mm design |
| F/2.904 design (f/2.8 nominal) |
| 2ω = 75.8° patent diagonal |
| 4 ASPHERICAL SURFACES |
Internal focus by the single positive G2 element (L7). For near focus L7 moves objectward: d13 decreases and d15 increases by the same amount; the close-focus endpoint is a paraxial fit to Leica's 0.30 m MFD.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | S-LAH99 (OHARA) |
| L2 | Neg. Meniscus (2× Asph) | K-VC80 (Sumita) / M-LAC130-class moldable lanthanum crown |
| L3 | Positive Meniscus | S-LAH55V (OHARA) |
| C1 | UV Resin Cement Layer | UV-curing resin (not counted as a glass element) |
| L4 | Negative Meniscus | S-TIH53 (OHARA) |
| L5 | Biconcave Negative | S-TIM35 (OHARA) |
| C2 | UV Resin Cement Layer | UV-curing resin (not counted as a glass element) |
| L6 | Biconvex Positive | S-LAH99 (OHARA) |
| L7 | Pos. Meniscus (2× Asph) | K-LaFK50-class (Sumita) / S-LAH66-class (OHARA) |
| L8 | Negative Meniscus | S-NPH1 (OHARA) |
Detailed analysis available in the interactive viewer above.