KONICA HEXANON AR 21mm f/2.8

JP 1980-017129 A, Example 1 — Toshiko Shimokura

9 ELEMENTS / 8 GROUPS
MODELED EFL 20.9973 mm
f/2.8
92° FULL FIELD
ALL-SPHERICAL

Focus Mechanism

NO_INTERNAL_RECONSTRUCTION — patent Example 1 is infinity-only; production MFD is 0.2 m from the film plane, but no internal focus movement is modeled.

Optical Elements (9 physical)

ElementTypeGlass
L1Positive Meniscus713539
L2Negative Meniscus720437
L3Negative Meniscus717479
L4Negative Meniscus717479
L5Biconvex Positive755275
L6Biconvex Positive603607
L7Biconcave Negative805254
L8Positive Meniscus697555
L9Positive Meniscus697555