MAMIYA-SEKOR MACRO C 80mm f/4

JP S55-24081 B2 — Masayoshi Okazaki

6 ELEMENTS / 4 GROUPS
f = 80.121 mm (DESIGN)
F/4
2ω = 47.195°
FLOATING FOCUS TO 1:2

Focus Mechanism

PUBLISHED floating-focus model using the patent beta=0 to beta=-1/2 internal gaps; the rear image distance is the independently solved finite conjugate. The bare lens reaches 1:2. The published beta=-1 state uses the optional Auto Macro Spacer and is not included.

Optical Elements (6 physical)

ElementTypeGlass
L1Positive Meniscus720502 — lanthanum crown (vendor unspecified)
L2Negative Meniscus575415 — light flint / TIL27-LF7 class (vendor unspecified)
L3Positive Meniscus620603 — SK16 / barium crown class (vendor unspecified)
L4Negative Meniscus699301 — SF15 / TIM35 dense flint class (vendor unspecified)
L5Positive Meniscus720502 — lanthanum crown (vendor unspecified)
L6Negative Meniscus673321 — SF5 / TIM25 dense flint class (vendor unspecified)