Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 328)

Note
Using these selection methods, you can manually select the initial AI Servo AF
position when [
: Initial Servo AF pt, / ] is set to [ Initial AF pt set for
/ ] ( ).
Pressing the < > button displays following information on the top LCD panel.
• Zone AF, Large Zone AF, and Automatic selection AF:
• Spot AF, 1-point AF, AF point expansion: (Center)/ (Off
center)
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