Canon EOS-1DX MARK II Settings Manual page 91

Group F (f/8 supported AF points)
AF is possible with all 61 points
Cross-type AF is possible with 21 points
AF focusing is possible with all 61 points. All AF area
selection modes can be chosen.
Major lens + extender combinations in Group F
EF400mm F2.8L IS II USM+ Ext EF2x
EF400mm F4 DO IS II USM+ Ext EF1.4x EF400mm F4 DO IS USM+ Ext EF1.4x
EF500mm F4L IS II USM+ Ext EF1.4x EF500mm F4L IS USM+ Ext EF1.4x
EF600mm F4L IS II USM+ Ext EF1.4x EF600mm F4L IS USM+ Ext EF1.4x
EF70-200mm F2.8L IS II USM+ Ext EF2x EF70-200mm F2.8L IS USM+ Ext EF2x
EF70-200mm F4L IS USM+ Ext EF1.4x
EF100-400mm F4.5-5.6L IS II USM+ Ext EF1.4x EF100-400mm F4.5-5.6L IS USM+ Ext EF1.4x
EF200-400mm F4L IS USM Ext 1.4x
Ext EF2xIII
EF400mm F4 DO IS II USM+ Ext EF2xIII EF400mm F4 DO IS USM+ Ext EF2xIII
EF400mm F5.6L USM+ Ext EF1.4xIII
EF500mm F4L IS USM+ Ext EF2xIII
EF600mm F4L IS USM+ Ext EF2xIII
EF600mm F4L USM+ Ext EF2xIII
EF400mm F2.8L II USM+ Ext EF2x
EF600mm F4L USM+ Ext EF1.4x
* "Ext EF1.4x" is an abbreviation of EF 1.4x Extender, and "Ext
EF2x" is an abbreviation of EF2x Extender. If no specific type (version
I, II, or III) is indicated after 1.4x or 2x, any version of that extender
can be used.
EF400mm F2.8L IS USM+ Ext EF2x
EF70-200mm F4L USM+ Ext EF1.4x
EF200-400mm F4L IS USM Ext 1.4x:
using built-in Ext + Ext EF1.4x III
EF500mm F4L IS II USM+ Ext EF2xIII
EF600mm F4L IS II USM+ Ext EF2xIII
EF500mm F4.5L USM+ Ext EF1.4xIII
EF300mm F2.8L USM+ Ext EF2x
EF400mm F2.8L USM+ Ext EF2x
EF70-200mm F2.8L USM+ Ext EF2x
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