PENTAX F 85mm f/2.8 Soft — Optical Cross-Section & Ray Tracing

Home / Lenses / Pentax / PENTAX F 85mm f/2.8 SoftPENTAX F 85mm f/2.8 SoftUS 5,267,086 Example 1 — Asahi Kogaku Kogyo / Hirano
5 ELEMENTS / 4 GROUPS
f ≈ 85.0 mm
F/2.8
2ω ≈ 28.4°
ALL SPHERICAL
Focus MechanismFront-group unit focus: L1–L4 translate forward as a rigid unit, L5 remains fixed relative to the film plane. AF via Pentax K-mount in-body motor.
Optical Elements (5)ElementTypeGlass
L1Positive MeniscusBACD14 (HOYA) / N-SSK5 equivalent (658509)
L2Negative MeniscusFD110 (HOYA) / S-TIH11 equivalent (785257)
L3Negative MeniscusFD60 (HOYA) / S-TIH10 equivalent (728285)
L4Biconvex PositiveS-LAH63 (OHARA)
L5Negative MeniscusBSC7 (HOYA)
AnalysisDetailed analysis available in the interactive viewer above.

Element	Type	Glass
L1	Positive Meniscus	BACD14 (HOYA) / N-SSK5 equivalent (658509)
L2	Negative Meniscus	FD110 (HOYA) / S-TIH11 equivalent (785257)
L3	Negative Meniscus	FD60 (HOYA) / S-TIH10 equivalent (728285)
L4	Biconvex Positive	S-LAH63 (OHARA)
L5	Negative Meniscus	BSC7 (HOYA)