Canon EOS M2 - Exposure

3 Setting Noise Reductiont
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 With [Auto] or [Enable], the noise reduction process after the picture is taken
may take the same amount of time as the exposure. During the noise
reduction process, “BUSY” will be displayed and you cannot take another
picture.
 Images taken at ISO 1600 or higher may look grainier with the [Enable]
setting than with the [Disable] or [Auto] setting.