US 6,115,188 A2000
Assignee: Canon Inc.
Inventors: Akihiro Nishio, Hideki Ogawa, Makoto Misaka
CANON EF 300mm f/2.8 L IS USM— 15 ACTIVE ELEMENTS / 11 GROUPS, MODELED EFL ≈ 293.600 mmCANON EF 400mm f/2.8 L IS USM— 400mm f/2.8 (marketed), Patent f = 392.15 mm, F/2.9CANON EF 500mm f/4 L IS USM— 15 MODELED ELEMENTS / 11 GROUPS, PATENT f = 490.56 mm; ARRAY EFL ≈ 491.36 mmCANON EF 600mm f/4 L IS USM— 15 modeled elements / 11 groups, Patent f = 585.20 mm; computed EFL ≈ 585.328 mm