CANON EXTENDER EF2X
2× rear teleconverter for Canon EF
JP S63-106715 A — Hideki Ogawa
7 ELEMENTS / 5 GROUPS | 2× REAR CONVERTER | ALL SPHERICAL
A dedicated converter: it mounts only on lenses made to accept it. A teleconverter has no aperture stop of its own, so it is shown attached to a host lens, where the lens's stop stays the system stop and the focal length and f-number both grow by the converter's factor.
Mount it on a lens (14 lenses)
CANON EF 100-400mm f/4.5-5.6 L IS II USM— 21 ELEMENTS / 16 GROUPS, PATENT ZOOM POINTS 102.79-389.03 mm, MODELED EFL 102.758-388.939 mmCANON EF 100-400mm f/4.5-5.6 L IS USM— 17 ELEMENTS / 14 PHYSICAL GROUPS, PATENT f = 102.68 / 161.53 / 389.19 mm, PATENT FNO = 4.6 / 5.1 / 5.8CANON EF 135mm f/2 L USM— 10 ELEMENTS / 8 GROUPS, 135 mm f/2 (marketing), f = 133.495 mm / F2.0598 (design)CANON EF 180mm f/3.5 L Macro USM— 14 ELEMENTS / 12 GROUPS, 180mm f/3.5 MARKETED, f = 180.009 mm / f/3.6 DESIGNCANON EF 200mm f/2 L IS USM— 17 elements / 12 groups incl. drop-in filter, f = 194.991 mm design; 200 mm marketed, F/2.05 design; f/2.0 marketedCANON EF 300mm f/2.8 L IS USM— 15 ACTIVE ELEMENTS / 11 GROUPS, MODELED EFL ≈ 293.600 mm, MODELED F/2.9CANON EF 400mm f/2.8 L IS II USM— 15 ACTIVE ELEMENTS / 11 GROUPS (PLUS REAR FILTER PLATE G), PATENT f = 392.15 mm; COMPUTED EFL 392.2607 mm, PATENT F/2.90 / MARKETED 400mm f/2.8CANON EF 400mm f/2.8 L IS USM— 400mm f/2.8 (marketed), Patent f = 392.15 mm, F/2.9, 17 elements / 13 groups marketed; 16 / 12 modeled plus drawn rear filterCANON EF 400mm f/4 DO IS USM— US 2002/0015231 A1 — Example 1, 15 powered elements / 11 active groups + rear plate, Design f = 392.025 mm, F/4.12CANON EF 600mm f/4 L IS II USM— 15 ACTIVE ELEMENTS / 11 GROUPS (PLUS REAR FILTER PLATE G), f = 584.82 mm (MODELED), F/4.12 DESIGNCANON EF 70-200mm f/2.8 L IS II USM— 23 elements / 19 groups, Patent f = 72.14-193.97 mm, Patent FNO = 2.9; marketed f/2.8CANON EF 70-200mm f/2.8 L IS USM— PATENT EXAMPLE: 21 ELEMENTS / 19 GROUPS, DESIGN 72.50-194.98 mm, DESIGN f/2.9CANON EF 70-200mm f/4 L IS USM— 20 ELEMENTS / 15 GROUPS, 70-200mm f/4 (MARKETED), 72.11-194.28mm f/4.1 (PATENT TABLE)CANON EF 70-200mm f/4 L USM— 16 ELEMENTS / 13 GROUPS, 70-200mm f/4 (MARKETED), 71.92-194.57mm f/4.1 (PATENT)