JP 2022-33487 A Example 1 — Sigma / Shioda
| 15 ELEMENTS / 11 GROUPS |
| f ≈ 33.72 mm (35 mm marketed) |
| F/1.4 |
| 2ω ≈ 67.78° |
| 2 ASPHERICAL SURFACES |
Inner focus by single-element negative middle group (L9), driven by stepping motor; lens length is fixed during focus and the front element does not rotate.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | HOYA FC5 (487/704) |
| L2 | Biconcave Negative | HOYA FCD100 (437/951) |
| L3 | Biconvex Positive | HOYA TAFD33 (881/401) |
| L4 | Biconvex Positive (1× Asph) | HOYA M-TAF105 (773/495) |
| L5 | Biconcave Negative | 593355 — heavy flint (vendor uncertain; no exact public catalog match) |
| L6 | Negative Meniscus | OHARA S-NBM51 (613/443) |
| L7 | Biconvex Positive | 459902 — HOYA FCD10A (ELD fluorophosphate crown; no coefficient-backed catalog entry yet) |
| L8 | Biconvex Positive | HOYA FCD705 (550/755) |
| L9 | Biconcave Negative | HOYA FC5 (487/704) |
| L10 | Negative Meniscus | HOYA NBFD25 (855/252) |
| L11 | Biconvex Positive | HOYA FCD705 (550/755) |
| L12 | Biconvex Positive | HOYA TAFD45 / OHARA S-LAH98 (953/323) |
| L13 | Biconcave Negative | OHARA S-NBM51 (613/443) |
| L14 | Biconvex Positive (1× Asph) | HOYA M-TAF105 (773/495) |
| L15 | Biconcave Negative | HOYA NBFD29 (770/297) |
Detailed analysis available in the interactive viewer above.