MAMIYA SEKOR AF 150mm f/2.8 IF D

JP 2001-183581 A — Hideyuki Suga

8 ELEMENTS / 7 GROUPS
f = 149.790 mm (DESIGN)
F/2.88 (DESIGN)
2ω = 26.5°
INNER FOCUS

Focus Mechanism

CONSTRAINED_RECONSTRUCTION: G1 is fixed; G2 (L4-L7 plus STO) and G3 (L8) move objectward. The 1.0 m endpoint preserves the fixed image plane and patent terminal X2/X3 = 0.7967231325, yielding |beta| = 0.1926159803. The patent-published |beta| = 0.15 state is not stored as the production endpoint.

Optical Elements (8 physical)

ElementTypeGlass
L1Positive MeniscusS-FPL51 (OHARA catalog model; supplier not established)
L2Positive MeniscusS-PHM52 (OHARA catalog model; supplier not established)
L3Negative MeniscusS-NBM51 (OHARA catalog model; supplier not established)
L4Positive MeniscusS-PHM52 (OHARA catalog model; supplier not established)
L5Biconcave NegativeS-NBH8 (OHARA catalog model; supplier not established)
L6Biconcave NegativeS-TIM5 (OHARA catalog model; supplier not established)
L7Biconvex PositiveUnmatched (nd=1.806098, νd=40.34; no exact current catalog identity)
L8Biconvex PositiveS-LAH66N (OHARA catalog model; supplier not established)