WO 2019/073744 A1 — Takuya Kato, Kota Omiya, Hiroyuki Matsumoto
| 13 elements / 10 groups |
| f = 23.66 mm patent design |
| F/1.44 design aperture |
| 2ω = 84.72° patent field |
| 4 aspherical surfaces on 2 elements |
| GR2 unit internal focus |
Internal focus by unit translation of GR2: d10 closes from 7.87 mm to 2.84 mm while d22 opens from 2.91 mm to 7.94 mm, moving GR2 5.03 mm toward the object at close focus.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus (2× Asph) | Unmatched (MC-TAF115-class; Hoya source nominal/polynomial conflict; patent nd=1.77002, νd=49.4) |
| L12 | Biconcave Negative | S-FPL51 (OHARA) |
| L13 | Biconvex Positive | S-LAH99 class (OHARA) |
| L14 | Biconcave Negative | S-TIH11 (OHARA) |
| L15 | Biconvex Positive | TAFD33 class (Hoya) |
| L21 | Biconvex Positive | S-FPL51 (OHARA) |
| L22 | Biconcave Negative | S-TIH13 (OHARA) |
| L23 | Biconvex Positive | S-FPL51 (OHARA) |
| L24 | Negative Meniscus | S-NBH53V (OHARA) |
| L25 | Biconvex Positive | S-LAH99 class (OHARA) |
| L26 | Negative Meniscus | SF2 (SCHOTT legacy catalog match; production glass unspecified) |
| L27 | Biconcave Negative (2× Asph) | M-TAFD305 (Hoya catalog equivalent; patent code 852401, supplier unspecified) |
| L31 | Biconvex Positive | PCD40 (Hoya) |