Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 83)

< >: AF Start Button/Smart Controller
On this control, you can press the center or drag with your finger.
Pressing the < > button activates autofocusing. This is equivalent to pressing
the shutter button halfway.
You can move the AF point by dragging on the smart controller after pressing the
<
> button. You can also adjust the sensitivity—the amount the AF point moves in
response to dragging ( ).
[ Direct AF point selection ] can be assigned to this control by selecting [ Smart
controller ] in [ 6 : Custom Controls ]. Assigning this function enables you to select an
AF point directly by dragging on the smart controller during metering, without pressing
the <
> button, and then pressing the < > button to focus.
Caution
Precautions when using the smart controller
In case of poor responsiveness if you are wearing gloves, use this control without
wearing the gloves.
The camera may not respond to touch operations with wet fingers.
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