Canon EOS 77D Mode D'emploi De Base page 120

3 Setting Noise ReductionN
Long Exposure Noise Reduction
Noise reduction is possible with images exposed for 1 sec. or longer.
[Auto]

For exposures of 1 sec. or longer, noise reduction is performed
automatically if noise typical of long exposures is detected. This
[Auto] setting is effective enough in most cases.
[Enable]

Noise reduction is performed for all exposures of 1 sec. or longer.
The [Enable] setting may reduce noise that cannot be detected with
the [Auto] setting.
118
Select [Long exp. noise
1
reduction].
Under the [z4] tab, select [Long

exp. noise reduction], then press
<0>.
Set the desired setting.
2
Select the desired setting, then press

<0>.
Take the picture.
3
The image will be recorded with noise

reduction applied.