The following pairs of images consist of a reduced size full image, and a crop taken at full resolution.
There’s no noticeable image noise at this minimum setting, but there is still evidence of noise reduction, which reduces fine detail.
There is colour noise in the shadow areas of this image, despite the heavy-handed noise reduction that has left the image looking like it was painted with a brush.
Look at the shadows under the bushes: colour noise everywhere. Also, look at the water at the foot of the weir, which has no fine detail.