Canon EOS-1DX Af Setting Manualbook page 123

Setting procedures
In [ISO speed settings] [Min. shutter spd.], you can select
the minimum shutter speed from 1/8000 sec. to 1 sec. in
1 step increments.
[AF tab 2]
From
[ISO speed settings]
Select
[Min. shutter spd.]
And choose a minimum
shutter speed
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