NIKON NIKKOR-O 2.1cm f/4 — Optical Cross-Section & Ray Tracing

Home / Lenses / Nikon / NIKON NIKKOR-O 2.1cm f/4NIKON NIKKOR-O 2.1cm f/4JP 1968-030782↗ — Zenji Wakimoto
8 ELEMENTS / 4 GROUPS
f = 21.000 mm
f/4
92° FULL FIELD
ALL SPHERICAL
Focus MechanismInferred unit focus to 0.9 m, modeled by increasing the final BF gap from 7.346550 to 7.875786 mm; the patent publishes only the infinity prescription.
Optical Elements (8 physical)ElementTypeGlass
L1Negative Meniscus (convex to object)620603 — SK16 / BSM16 / BACD16 class
L2Biconvex Positive723380 — BAFD8 / S-BAH28 / J-BASF8 class
L3Biconcave Negative648338 — SF2 / E-FD2 / J-SF2 class
L4Biconvex PositiveLF3 (Sumita coefficient-backed equivalent), 582420
L5Positive Meniscus (convex to image)518588–518590 — K3 / C3 / NSL3 class
L6Biconcave Negative648338 — SF2 / E-FD2 / J-SF2 class
L7Biconvex Positive723380 — BAFD8 / S-BAH28 / J-BASF8 class
L8Negative Meniscus (convex to image)LAK6 (Sumita coefficient-backed equivalent), 643581

Element	Type	Glass
L1	Negative Meniscus (convex to object)	620603 — SK16 / BSM16 / BACD16 class
L2	Biconvex Positive	723380 — BAFD8 / S-BAH28 / J-BASF8 class
L3	Biconcave Negative	648338 — SF2 / E-FD2 / J-SF2 class
L4	Biconvex Positive	LF3 (Sumita coefficient-backed equivalent), 582420
L5	Positive Meniscus (convex to image)	518588–518590 — K3 / C3 / NSL3 class
L6	Biconcave Negative	648338 — SF2 / E-FD2 / J-SF2 class
L7	Biconvex Positive	723380 — BAFD8 / S-BAH28 / J-BASF8 class
L8	Negative Meniscus (convex to image)	LAK6 (Sumita coefficient-backed equivalent), 643581