Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 213)

High ISO Speed Noise Reduction
You can reduce the image noise generated. This function is especially effective when
shooting at high ISO speeds. When shooting at low ISO speeds, the noise in the darker
parts of the image (shadow areas) can further be reduced.
1.
Select [ : High ISO speed NR].
2.
Set the level.
Low, Standard, High
The camera applies an amount of noise reduction corresponding to
your specified level.
Multi Shot Noise Reduction
Applies noise reduction with higher image quality than [ High ]. For a
single photo, four shots are taken continuously and aligned and
merged automatically into a single JPEG image.
Note that [
Multi Shot Noise Reduction ] is not available with image
quality set to RAW or RAW+JPEG.
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