NIKON NIKKOR Z 20mm f/1.8 S

WO 2021/117429 A1 — Fumiaki Ohtake

20 mm
f/1.8
14 elements / 11 groups
3 ED elements
3 aspherical elements
Multi-FS

Focus Mechanism

PUBLISHED focus model: G2 moves imageward while G4 moves objectward from infinity to the near row. The patent also publishes a middle row (D8=4.66117, D10=8.86123, D23=7.83192, D25=8.21231), documented in the data header; the current LensData var schema stores the infinity and near endpoints.

Optical Elements (14 physical; 15 modeled media)

ElementTypeGlass
L11Negative MeniscusS-LAL14 (OHARA; coordinate match)
L12gNegative Meniscus773496 class (HIKARI J-LASF016 coordinate representative)
L12rNeg. Meniscus (1× Asph)Unmatched (hybrid resin layer; patent nd=1.51380, νd=52.97)
L13Biconcave NegativeJ-FKH1 (HIKARI; coordinate match)
L14Positive MeniscusJ-LASFH21 (HIKARI; coordinate match)
L21Biconvex PositiveJ-LASF015 (HIKARI; coordinate match)
L31Biconvex PositiveJ-LASFH21 (HIKARI; coordinate match)
L32Biconcave NegativeJ-SF03 (HIKARI; coordinate match)
L33Biconcave NegativeJ-SF7 (HIKARI; coordinate match)
L34Biconvex PositiveJ-FKH1 (HIKARI; coordinate match)
L35Biconvex PositiveJ-FKH1 (HIKARI; coordinate match)
L36Negative MeniscusJ-LASFH21 (HIKARI; coordinate match)
L37Biconvex PositiveS-TIH57 (OHARA; coordinate match)
L41Neg. Meniscus (2× Asph)L-LAH94 (OHARA; coordinate match)
L51Neg. Meniscus (2× Asph)L-LAH94 (OHARA; coordinate match)