Canon EOS REBEL T8i, Advanced User'S Manual, Page: 155 / 775

Exposure Compensation with ISO Auto
If the ISO speed is set to “ ” (AUTO) for manual exposure shooting, you can set exposure
compensation (
) as follows:
[ : Expo.comp./AEB ]
By holding down < > and turning the < > dial when [ ] in the [ 13: Custom
Controls ] setting of [ : Custom Functions(C.Fn) ] is set to [ Expo comp (hold
btn, turn ) ].
Quick Control screen
Caution
Exposure may not be as expected when ISO Auto is set, because the ISO speed is
adjusted to ensure standard exposure for your specified shutter speed and
aperture value. In this case, set the exposure compensation.
Exposure compensation is not applied in flash photography with ISO Auto, even if
you have set an exposure compensation amount.
Note
To enable Auto Lighting Optimizer to be specified in < > mode as well, clear the
[ ] mark for [ Disable during man expo ] in [ : Auto Lighting Optimizer ] ( ).
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 <
>
mode with ISO Auto after using exposure compensation in < >, < >, or
< > mode ( ).
To coordinate exposure compensation in ½-stop increments with ISO speed set in
⅓-stop increments when [
1: Exposure level increments ] in [ : Custom
Functions(C.Fn) ] is set to [ 1:1/2-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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