JP2021-43376A EXAMPLE 5 — COSINA / SUGANO
| 10 ELEMENTS / 8 GROUPS |
| f ≈ 49.3 mm |
| F/1.93 |
| 2ω ≈ 47.4° |
| 4 ASPHERICAL SURFACES |
| 5 APD ELEMENTS (Z/E-MOUNT) |
Floating focus (F36 scheme) — front group, Jb, and Ja+LE move independently. Three variable air gaps adjust to maintain quasi-symmetric aberration balance.
| Element | Type | Glass |
|---|---|---|
| LF | Biconcave Negative | Unmatched (likely Sumita proprietary) |
| Lfa | Pos. Meniscus (2× Asph) | Unmatched (dense lanthanum; nd=1.852/νd=42.1 unregistered across OHARA, Schott, Hoya, Sumita public catalogs) |
| Lfb | Biconvex Positive | S-FPL51 / N-PK52A (universal) |
| Lfc | Biconvex Positive | FCD505 (HOYA) / K-GFK68 (Sumita) |
| Lfd | Negative Meniscus | Unmatched (likely Sumita proprietary) |
| Lrd | Biconcave Negative | Unmatched (KZFS-adjacent, dPgF ≈ −0.01 est.) |
| Lrc | Biconvex Positive | Unmatched (S-LAH64-type lanthanum; nd=1.793/νd=47.2; S-LAH64 not in catalog) |
| Lrb | Biconvex Positive | Unmatched (lanthanum; nd=1.803/νd=46.6; S-LAH65V catalog nd=1.804 exceeds 1e-4 tolerance) |
| Lra | Biconcave Negative | Unmatched (conventional) |
| LE | Neg. Meniscus (2× Asph) | S-BSL7 / N-BK7 (universal) |
Detailed analysis available in the interactive viewer above.