Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 908)

Compatible Lenses and Autofocusing (Viewfinder
Shooting)
Group A
Group B
Group C
Group D
Group E
Group F
Group G
Group H
Group I
Group J
Group Classification of Lenses
Caution
Although the camera has 191 AF points, lenses are classified into 10 groups (A–
J) which vary in the number of AF points available, AF point patterns, Area
AF frame shapes, and other details.
When lenses in groups F–J are used, fewer AF points are available.
See
Group Classification of Lenses for lenses you will use.
Note
AF points in positions indicated by [ ] blink when the < > button is pressed
(while [ / / ] points remain lit). For details on AF point blinking/illumination, see
Meaning of Lit or Blinking AF Points .
For updates on “Group Classification of Lenses,” visit the Canon website or others.
Some lenses may not be available in certain countries or regions.
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