NIKON AI AF ZOOM-NIKKOR 20-35mm f/2.8D IF — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON AI AF ZOOM-NIKKOR 20-35mm f/2.8D IFNIKON AI AF ZOOM-NIKKOR 20-35mm f/2.8D IFUS 5,276,553 A↗ — Wataru Tatsuno
14 ELEMENTS / 11 AIR-SEPARATED UNITS / 4 ZOOM GROUPS
20-35mm MARKETED / 20.5-34.0mm PATENT DESIGN
f/2.8 MARKETED / F/2.89 PATENT DESIGN
35mm FULL-FRAME / NIKON F
1 ASPHERICAL SURFACE
Focus MechanismNO_INTERNAL_RECONSTRUCTION — US 5,276,553 identifies cemented L21 as the internal focusing component, but publishes no finite-focus spacing table or travel. The authored zoom states therefore remain infinity-focus only; the 0.5 m production minimum focus distance is catalog metadata and does not drive a reconstructed focus state.
Optical Elements (14 physical)ElementTypeGlass
L11Negative Meniscus (1× Asph)J-LASF016 catalog equivalent (production supplier not established; patent 773494)
L12Biconcave NegativeTAF4 catalog equivalent (production supplier not established; patent 788475)
L13Biconvex PositiveE-LAF11 catalog equivalent (production supplier not established; patent 757316)
L14Positive MeniscusE-LAF11 catalog equivalent (production supplier not established; patent 757316)
L21aNegative MeniscusSF1 catalog equivalent (production supplier not established; patent 717295)
L21bBiconvex PositiveJ-PKH1 catalog equivalent (production supplier not established; patent 519699)
L22Positive MeniscusLAC8 catalog equivalent (production supplier not established; patent 713539)
L31aBiconcave Negative748523 — E-LAKH1 catalog equivalent (Hikari; production supplier unspecified)
L31bPositive MeniscusS-TIH6 catalog equivalent (production supplier not established; patent 805254)
L41Positive MeniscusJ-SSK5 catalog equivalent (production supplier not established; patent 658508)
L42Negative MeniscusSF56A catalog equivalent (production supplier not established; patent 785261)
L43Biconvex PositiveJ-LASF017 catalog equivalent (production supplier not established; patent 797454)
L44aBiconvex PositiveS-BSM10 catalog equivalent (production supplier not established; patent 623570)
L44bNegative MeniscusJ-SFH2 catalog equivalent (production supplier not established; patent 861230)

Element	Type	Glass
L11	Negative Meniscus (1× Asph)	J-LASF016 catalog equivalent (production supplier not established; patent 773494)
L12	Biconcave Negative	TAF4 catalog equivalent (production supplier not established; patent 788475)
L13	Biconvex Positive	E-LAF11 catalog equivalent (production supplier not established; patent 757316)
L14	Positive Meniscus	E-LAF11 catalog equivalent (production supplier not established; patent 757316)
L21a	Negative Meniscus	SF1 catalog equivalent (production supplier not established; patent 717295)
L21b	Biconvex Positive	J-PKH1 catalog equivalent (production supplier not established; patent 519699)
L22	Positive Meniscus	LAC8 catalog equivalent (production supplier not established; patent 713539)
L31a	Biconcave Negative	748523 — E-LAKH1 catalog equivalent (Hikari; production supplier unspecified)
L31b	Positive Meniscus	S-TIH6 catalog equivalent (production supplier not established; patent 805254)
L41	Positive Meniscus	J-SSK5 catalog equivalent (production supplier not established; patent 658508)
L42	Negative Meniscus	SF56A catalog equivalent (production supplier not established; patent 785261)
L43	Biconvex Positive	J-LASF017 catalog equivalent (production supplier not established; patent 797454)
L44a	Biconvex Positive	S-BSM10 catalog equivalent (production supplier not established; patent 623570)
L44b	Negative Meniscus	J-SFH2 catalog equivalent (production supplier not established; patent 861230)