NIKON NIKKOR 28mm f/2.8 (Nikon 28Ti) — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON NIKKOR 28mm f/2.8 (Nikon 28Ti)NIKON NIKKOR 28mm f/2.8 (Nikon 28Ti)US 5,528,428↗, Embodiment 3 — Motoyuki Ohtake, Motohisa Mouri
7 ELEMENTS / 5 GROUPS
f ≈ 28.9 mm
F/2.87
2ω ≈ 74.0°
ALL SPHERICAL
Focus MechanismUnit focus — the whole lens moves axially (patent whole-axial-movement system); close extension calculated for a 0.40 m film-plane MFD.
Optical Elements (7 physical)ElementTypeGlass
L1Negative MeniscusJ-LLF6 (HIKARI catalog equivalent; LLF6-class light flint 532491, vendor unspecified)
L2aBiconvex Positive840433 - lanthanum flint (catalog unresolved; patent nd=1.84042, vd=43.3)
L2bBiconcave NegativeE-FD2 (HOYA catalog equivalent; SF2-class dense flint, patent 648338, vendor unspecified)
L3aBiconvex PositiveJ-LASF09A (HIKARI catalog equivalent; LAH59-class lanthanum crown 816468, vendor unspecified)
L3bBiconcave Negative617308 - high-dispersion flint (catalog unresolved; patent nd=1.61750, vd=30.8)
L4Positive MeniscusJ-LASF017 (Hikari catalog-equivalent to patent 797454; supplier not identified)
L5Negative MeniscusS-FTM16 (OHARA catalog equivalent; patent 595355, Δnd −0.0024, vendor unspecified)

Element	Type	Glass
L1	Negative Meniscus	J-LLF6 (HIKARI catalog equivalent; LLF6-class light flint 532491, vendor unspecified)
L2a	Biconvex Positive	840433 - lanthanum flint (catalog unresolved; patent nd=1.84042, vd=43.3)
L2b	Biconcave Negative	E-FD2 (HOYA catalog equivalent; SF2-class dense flint, patent 648338, vendor unspecified)
L3a	Biconvex Positive	J-LASF09A (HIKARI catalog equivalent; LAH59-class lanthanum crown 816468, vendor unspecified)
L3b	Biconcave Negative	617308 - high-dispersion flint (catalog unresolved; patent nd=1.61750, vd=30.8)
L4	Positive Meniscus	J-LASF017 (Hikari catalog-equivalent to patent 797454; supplier not identified)
L5	Negative Meniscus	S-FTM16 (OHARA catalog equivalent; patent 595355, Δnd −0.0024, vendor unspecified)