Canon EOS 6D Mark II Mode D'emploi page 127

ISO Auto
Shooting Modes
A/C
8
d/s/f/a
F
* The actual ISO speed range depends on the [Minimum] and [Maximum] set
with [Auto range].
If the ISO speed is set to "A" (Auto), the
actual ISO speed to be set will be
displayed when you press the shutter
button halfway.
As indicated below, the ISO speed will
be set automatically to suit the shooting
mode.
No Flash
ISO 100 - ISO 12800
(Varies depending on the 8 shooting mode)
ISO 100 - ISO 40000*
ISO 400*
i: Setting the ISO Speed for Still PhotosN
ISO Speed
ISO 100 - ISO 1600
Automatically set
ISO 100 - ISO 1600*
ISO 400*
With Flash
125