NIKON R-UW AF ZOOM-NIKKOR 20-35mm f/2.8 — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON R-UW AF ZOOM-NIKKOR 20-35mm f/2.8NIKON R-UW AF ZOOM-NIKKOR 20-35mm f/2.8US 5,490,012↗ — Kouichi Ohshita
10 elements / 10 groups
f = 20.60-34.00 mm in water
F/2.88 design aperture
2ω = 79.8°-51.4° in water
All-spherical underwater zoom
Focus MechanismPatent-described G2 focusing; close-focus spacings are unpublished, so this file models verified infinity zoom positions only.
Optical Elements (10 physical)ElementTypeGlass
L1Positive Meniscus / Water-contact WindowN-BK7 (Schott; BK7-class, patent nd/vd match)
L2Negative MeniscusJ-LASF017 (Hikari catalog-equivalent to patent 797454; supplier not identified)
L3Plano-Concave NegativeM-TAF1 class (Hoya; 773/494)
L4Positive MeniscusN-SF1 / S-TIH1 class (dense flint)
L5Biconvex PositiveJ-BASF6 (Hikari) / BAH26 class (668419)
L6Positive MeniscusN-SK16 (Schott) / S-BSM16 class
L7Biconcave NegativeN-SF6 (Schott) / S-TIH6 class
L8Positive MeniscusS-LAL14 (Ohara) / N-LAK14 class
L9Biconvex Positive748523 — E-LAKH1 catalog equivalent (Hikari; production supplier unspecified)
PPlane Parallel PlateN-BK7 (Schott; BK7-class, patent nd/vd match)

Element	Type	Glass
L1	Positive Meniscus / Water-contact Window	N-BK7 (Schott; BK7-class, patent nd/vd match)
L2	Negative Meniscus	J-LASF017 (Hikari catalog-equivalent to patent 797454; supplier not identified)
L3	Plano-Concave Negative	M-TAF1 class (Hoya; 773/494)
L4	Positive Meniscus	N-SF1 / S-TIH1 class (dense flint)
L5	Biconvex Positive	J-BASF6 (Hikari) / BAH26 class (668419)
L6	Positive Meniscus	N-SK16 (Schott) / S-BSM16 class
L7	Biconcave Negative	N-SF6 (Schott) / S-TIH6 class
L8	Positive Meniscus	S-LAL14 (Ohara) / N-LAK14 class
L9	Biconvex Positive	748523 — E-LAKH1 catalog equivalent (Hikari; production supplier unspecified)
P	Plane Parallel Plate	N-BK7 (Schott; BK7-class, patent nd/vd match)