NIKON AI NIKKOR 180mm f/2.8 ED — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON AI NIKKOR 180mm f/2.8 EDNIKON AI NIKKOR 180mm f/2.8 EDUS 4,338,001 Embodiment 2 — Sei Matsui / Nippon Kogaku
5 elements / 5 groups
f = 180.00 mm, scaled from patent f = 100
f/2.8, all-spherical
2ω = 13.6°
Unit focus model
Focus MechanismUnit focus. The whole optical unit translates; only the final back-focus gap varies from infinity to the 1.8 m close-focus setting.
Optical Elements (5)ElementTypeGlass
L1Biconvex PositiveUnmatched Nikon ED fluorophosphate (near S-FPL51/FCD1 class; nd offset +0.0033)
L2Biconcave NegativeLAFN7 / E-LAF7 class (750/350 lanthanum flint)
L3Positive MeniscusN-SSK5 / S-BSM25 class (658/509 dense barium crown)
L4Negative MeniscusKF3-class crown-flint (obsolete Schott KF3-type; nd=1.51454, νd≈54.6)
L5Biconvex PositiveUnmatched (TAF/LaSF-class high-index flint, nd=1.79668, νd=45.4; near HOYA TAF2 / HIKARI J-LASF017)
AnalysisDetailed analysis available in the interactive viewer above.

Element	Type	Glass
L1	Biconvex Positive	Unmatched Nikon ED fluorophosphate (near S-FPL51/FCD1 class; nd offset +0.0033)
L2	Biconcave Negative	LAFN7 / E-LAF7 class (750/350 lanthanum flint)
L3	Positive Meniscus	N-SSK5 / S-BSM25 class (658/509 dense barium crown)
L4	Negative Meniscus	KF3-class crown-flint (obsolete Schott KF3-type; nd=1.51454, νd≈54.6)
L5	Biconvex Positive	Unmatched (TAF/LaSF-class high-index flint, nd=1.79668, νd=45.4; near HOYA TAF2 / HIKARI J-LASF017)