PENTAX HD D FA645 MACRO 90mm f/2.8 ED AW SR

US 2013/0222925 A1 — Tatsuyuki Onozaki, Masakazu Saori

11 ELEMENTS / 9 GROUPS
f = 90.116 mm (DESIGN)
F/2.85 (DESIGN)
2ω = 42.2°
0.5x AT 0.413 m
1 ASPHERICAL SURFACE

Focus Mechanism

PUBLISHED two-group floating focus. From infinity to -0.50:1, G1 and G2 move objectward by 35.368 mm and 29.090 mm; D15 changes 5.680-11.958 mm and BFD changes 69.090-98.180 mm.

Optical Elements (11 physical)

ElementTypeGlass
L11Negative Meniscus835427 - high-index lanthanum glass class (vendor unresolved)
L12Positive Meniscus806333 - high-index lanthanum flint class (vendor unresolved)
L13Biconvex Positive497816 - ED fluorophosphate crown class (vendor unresolved)
L14Biconcave Negative640346 - E-FD7/S-TIM27-class dense flint (code equivalent)
L15Positive Meniscus805255 - dense flint class (vendor unresolved)
L16Biconcave Negative728283 - dense flint class (vendor unresolved)
L17Biconvex Positive497816 - ED fluorophosphate crown class (vendor unresolved)
L18Biconvex Positive (1x Asph)806407 - high-index lanthanum glass class (vendor unresolved)
L21Negative Meniscus640346 - E-FD7/S-TIM27-class dense flint (code equivalent)
L22Biconvex Positive806333 - high-index lanthanum flint class (vendor unresolved)
L23Biconcave Negative569560 - barium crown class (vendor unresolved)