US 2026/0118637 A1 Example 4
| 23mm |
| f/2.8 |
| 8 elements / 6 groups |
| 2 aspherical elements |
| APS-C |
Unit/full-group focus. Patent Example 4 moves the full optical system and changes only DD[15] from 11.087 mm at infinity to 14.713 mm at beta = -0.16x.
| Element | Type | Glass |
|---|---|---|
| L11 | Biconcave Negative (2x Asph) | BK7 / BSL7-class borosilicate crown (516/641, catalog-class) |
| L12 | Biconvex Positive | S-LAH66-class lanthanum flint (OHARA 773/496 class) |
| L21 | Biconcave Negative | 730322 - NBFD32 (HOYA dense barium flint; no Sellmeier catalog entry) |
| L22 | Biconvex Positive | TAFD32-class dense tantalum flint (871/407) |
| L23 | Biconvex Positive | S-LAH59 / TAF5 / ZLaF54-class lanthanum flint (816/466) |
| L24 | Biconcave Negative | SF2 / E-FD2-class dense flint (648/339) |
| L25 | Negative Meniscus | F2 / E-F2-class flint (620/363) |
| L26 | Near Plano-Convex Positive (2x Asph) | NBFD13 / M-NBFD130 (HOYA, 806407 code) |
Detailed analysis available in the interactive viewer above.