OLYMPUS ZUIKO AUTO-FISHEYE 8mm f/2.8 — Optical Cross-Section & Ray Tracing

Home / Lenses / Olympus / OLYMPUS ZUIKO AUTO-FISHEYE 8mm f/2.8OLYMPUS ZUIKO AUTO-FISHEYE 8mm f/2.8DE 2157160 A1↗ — Jihei Nakagawa
Patent Example 1: 10 elements / 6 groups
Production correlation: 8mm f/2.8 OM circular fisheye
180° field, 23 mm circular image
All-spherical prescription
Focus MechanismUnit-focus approximation. The patent publishes only the infinity prescription; runtime focus varies the final back-focus gap after surface 16.
Optical Elements (10 physical)ElementTypeGlass
L1Negative MeniscusS-BAL35 class (OHARA; SK5 / 589/610 equivalent)
L2Positive MeniscusS-TIH11 class (OHARA; SF11 / 785/256 equivalent)
L3Negative MeniscusS-BAL35 class (OHARA; SK5 / 589/610 equivalent)
L4Negative MeniscusJ-LAK02 class (Hikari; 670/573)
L5Positive MeniscusH-ZF39 class (CDGM; 667/330)
L6Negative MeniscusYGH52 (OHARA catalog-equivalent; patent supplier unspecified)
L7Biconvex PositiveBAM25 (OHARA catalog-equivalent; patent supplier unspecified)
L8Positive MeniscusJ-PKH1 class (Hikari; 517/693 low-dispersion crown)
L9Negative MeniscusN-SF66 class (SCHOTT; 923/209 very dense flint)
L10Biconvex PositiveJ-PKH1 class (Hikari; 517/693 low-dispersion crown)

Element	Type	Glass
L1	Negative Meniscus	S-BAL35 class (OHARA; SK5 / 589/610 equivalent)
L2	Positive Meniscus	S-TIH11 class (OHARA; SF11 / 785/256 equivalent)
L3	Negative Meniscus	S-BAL35 class (OHARA; SK5 / 589/610 equivalent)
L4	Negative Meniscus	J-LAK02 class (Hikari; 670/573)
L5	Positive Meniscus	H-ZF39 class (CDGM; 667/330)
L6	Negative Meniscus	YGH52 (OHARA catalog-equivalent; patent supplier unspecified)
L7	Biconvex Positive	BAM25 (OHARA catalog-equivalent; patent supplier unspecified)
L8	Positive Meniscus	J-PKH1 class (Hikari; 517/693 low-dispersion crown)
L9	Negative Meniscus	N-SF66 class (SCHOTT; 923/209 very dense flint)
L10	Biconvex Positive	J-PKH1 class (Hikari; 517/693 low-dispersion crown)