PANASONIC LUMIX G 25mm f/1.7 ASPH. — Optical Cross-Section & Ray Tracing

Home / Lenses / Panasonic / PANASONIC LUMIX G 25mm f/1.7 ASPH.PANASONIC LUMIX G 25mm f/1.7 ASPH.US 2017/0059832 A1↗ — Shunichiro Yoshinaga
8 elements / 7 groups
f = 25.878 mm design / 25 mm nominal
F/1.760 design / f/1.7 nominal
2ω = 47.26° patent field
4 aspherical surfaces on 2 elements
Focus MechanismInner focus: the single negative L6 element (G2) moves imageward; patent cover glass is folded into the final air-equivalent BF.
Optical Elements (8 physical)ElementTypeGlass
L1Positive MeniscusTAFD40 (Hoya) / H-ZLaF90 class
L2Negative MeniscusE-CF6 (Hoya) / S-NSL36 class
L3Biconcave NegativeFF8 (Hoya, 752/251)
L4Biconvex PositiveTAC8 (Hoya) / S-LAL18 class
L5Biconvex PositiveTAF3 (Hoya) / N-LASF44 class
L6Neg. Meniscus (2× Asph)Unmatched (53380/55.6 anomalous PGM crown; patent line indices)
L7Biconvex Positive (2× Asph)Unmatched (53380/55.6 anomalous PGM crown; patent line indices)
L8Negative MeniscusE-FL5 (Hoya) / S-TIL25 class

Element	Type	Glass
L1	Positive Meniscus	TAFD40 (Hoya) / H-ZLaF90 class
L2	Negative Meniscus	E-CF6 (Hoya) / S-NSL36 class
L3	Biconcave Negative	FF8 (Hoya, 752/251)
L4	Biconvex Positive	TAC8 (Hoya) / S-LAL18 class
L5	Biconvex Positive	TAF3 (Hoya) / N-LASF44 class
L6	Neg. Meniscus (2× Asph)	Unmatched (53380/55.6 anomalous PGM crown; patent line indices)
L7	Biconvex Positive (2× Asph)	Unmatched (53380/55.6 anomalous PGM crown; patent line indices)
L8	Negative Meniscus	E-FL5 (Hoya) / S-TIL25 class