OLYMPUS ZUIKO AUTO-W 18mm f/3.5

US 4,029,397 — Nobuo Yamashita

11 ELEMENTS / 9 GROUPS
18.03 mm PARAXIAL EFL
f/3.5
100° DIAGONAL FIELD
FLOATING REAR GROUP
ALL SPHERICAL

Focus Mechanism

Floating rear group: L3-L11 advances toward the fixed L1-L2 front group; the final BFD increases by the same amount.

Optical Elements (11 physical)

ElementTypeGlass
L1Positive MeniscusS-LAL12 (OHARA; coordinate match)
L2Negative MeniscusS-LAH51 (OHARA; coordinate match)
L3Negative MeniscusS-LAH51 (OHARA; coordinate match)
L4Negative MeniscusS-LAH51 (OHARA; coordinate match)
L5Biconvex PositiveS-TIL26 (OHARA; coordinate match)
L6Negative MeniscusS-LAL14 (OHARA; coordinate match)
L7Biconvex PositiveS-FTM16 class (OHARA; closest current coordinate match)
L8Positive MeniscusS-LAH51 (OHARA; coordinate match)
L9Biconcave NegativeSF57 (SCHOTT; coordinate match)
L10Positive MeniscusS-PHM52 (OHARA; coordinate match)
L11Positive MeniscusS-PHM52 (OHARA; coordinate match)