WO 2017/130571 A1 — Masaki Maruyama, Hiroyuki Matsumoto
| 11 ELEMENTS / 8 GROUPS |
| DESIGN f = 86.85 mm |
| DESIGN F/1.45 |
| 1 ASPHERICAL SURFACE / 1 ELEMENT |
| INNER FOCUS (G2) |
Inner focus: G2 (L5–L8, two cemented doublets) moves 12.10 mm toward the object from infinity to the patent's 0.85 m state while G1, the stop and G3 stay fixed. The published close gaps focus at about 0.858 m object-to-image in this model; Sony's 0.8 m manual-focus limit is not modeled.
| Element | Type | Glass |
|---|---|---|
| L1 | Positive Meniscus | PCD4 (HOYA) / dense phosphate crown class (cf. H-ZPK1A, K-PSKn2, N-PSK53A; Δνd −0.008 to −0.011) |
| L2 | Positive Meniscus | FCD1 (HOYA) / fluorophosphate ED class (N-PK52A, H-FK61 coordinates; cf. S-FPL51) |
| L3 | Positive Meniscus | FCD515 (HOYA) / ED phosphate crown class (no coordinate-exact non-HOYA match) |
| L4 | Negative Meniscus | E-F2 (HOYA) / F2-type flint class (cf. S-TIM2) |
| L5 | Biconcave Negative | E-F2 (HOYA) / F2-type flint class (cf. S-TIM2) |
| L6 | Positive Meniscus | TAFD55 (HOYA) / nd 2.00 lanthanum dense flint class (cf. J-LASFH16, S-LAH99; Δνd −0.007, +0.009) |
| L7 | Neg. Meniscus (1× Asph) | M-FDS910 (HOYA, precision-moulding dense flint; inferred) |
| L8 | Biconvex Positive | FCD515 (HOYA) / ED phosphate crown class (no coordinate-exact non-HOYA match) |
| L9 | Biconvex Positive | TAFD55 (HOYA) / nd 2.00 lanthanum dense flint class (cf. J-LASFH16, S-LAH99; Δνd −0.007, +0.009) |
| L10 | Biconcave Negative | E-FD4 (HOYA) / dense flint class (H-ZF6 coordinates; cf. S-TIH4) |
| L11 | Negative Meniscus | BAC4 (HOYA) / barium crown class (H-BaK7 coordinates; cf. N-BAK4) |