NIKON NIKKOR-N AUTO 28mm f/2 — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON NIKKOR-N AUTO 28mm f/2NIKON NIKKOR-N AUTO 28mm f/2US 3,736,049↗, sole example — Yoshiyuki Shimizu
9 ELEMENTS / 8 GROUPS
f ≈ 27.8 mm (design)
F/2.0
2ω ≈ 74.5°
ALL SPHERICAL
Focus MechanismCRC (Close-Range Correction): the converter-to-master gap d9 closes by the published 0.616 mm at β = −1/10 (≈0.37 m) while the whole lens extends; the 0.3 m production MFD keyframe holds that d9 and is calculated.
Optical Elements (9 physical)ElementTypeGlass
L1Negative MeniscusS-BSM15 (OHARA)
L2Positive MeniscusLAF2 (Schott) / S-LAM2 (OHARA)
L3Negative MeniscusS-BSM15 (OHARA)
L4Biconvex PositiveE-LASF016 (Hikari) / J-LASF016 / LACL60 class
L5Biconcave NegativeJ-BK7A (HIKARI catalog equivalent; patent 1.51680 / 64.2, vendor unspecified)
L6Biconvex PositiveJ-BK7A (HIKARI catalog equivalent; patent 1.51680 / 64.2, vendor unspecified)
L7Biconcave NegativeFDS9 (HOYA) / SF56A (Schott)
L8Positive Meniscus744479 — lanthanum flint (catalog unresolved; nd = 1.74443, νd = 47.9)
L9Biconvex PositiveLAK8 (Schott) / S-LAL8 (OHARA)

Element	Type	Glass
L1	Negative Meniscus	S-BSM15 (OHARA)
L2	Positive Meniscus	LAF2 (Schott) / S-LAM2 (OHARA)
L3	Negative Meniscus	S-BSM15 (OHARA)
L4	Biconvex Positive	E-LASF016 (Hikari) / J-LASF016 / LACL60 class
L5	Biconcave Negative	J-BK7A (HIKARI catalog equivalent; patent 1.51680 / 64.2, vendor unspecified)
L6	Biconvex Positive	J-BK7A (HIKARI catalog equivalent; patent 1.51680 / 64.2, vendor unspecified)
L7	Biconcave Negative	FDS9 (HOYA) / SF56A (Schott)
L8	Positive Meniscus	744479 — lanthanum flint (catalog unresolved; nd = 1.74443, νd = 47.9)
L9	Biconvex Positive	LAK8 (Schott) / S-LAL8 (OHARA)