Canon EOS R6 Mark II Mirrorless Camera with 24-105mm f/4-7.1 Lens - Manual (Page 149)

Note
ISO speed is locked when you hold down the shutter button halfway after subjects
are in focus with One-Shot AF in <
M > mode with ISO Auto, < > (evaluative
metering), and [ : AE lock meter. mode after focus ] set to the default setting
( ).
When ISO Auto is set, you can press the < > button to lock the ISO speed.
If you press the < > button and recompose the shot, you can see the exposure
level difference on the exposure level indicator compared to when the < >
button was pressed.
Any existing exposure compensation amount is maintained if you switch to <
M >
mode with ISO Auto after using exposure compensation in < P >, < Tv >, or < Av >
mode ( ).
To coordinate exposure compensation in ½-stop increments with ISO speed set in
⅓-stop increments when [
: Exposure level increments ] is set to [ 1/2-stop ] and
used with ISO Auto, exposure compensation is further adjusted by adjusting shutter
speed. However, the shutter speed displayed will not change.
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