When QU v2018.121 was released a last week, the release notes said, in addition to improved Noise reduction, "New 'ANR' checkbox in raw refine allows auto noise reduction to be turned off on a per-image basis: useful for custom post-processing of noise.".
I wondered what that really meant but after having some problems with noisy 1600 iso macro images I asked Mike for help which he duly gave and enabled me to get a satisfactory result by un-ticking the ANR box in Raw Refine and using the NR tools in the image editor.
These tools are shadow noise NR, medium NR and Ultra NR which has 5 levels within it. Not only that, Deep Focus Sharpening in conjunction with Tone Targeted Sharpening can soften areas that are noisy. See attached screen shot.
Mike explained why this method can be better with noisy images:-
"the reason you'd want to turn ANR off in refine is so the noise still looks like noise in the editor. When removing heavier noise in the editor or being creative, you don't want refine to make the noise look like something else: otherwise the noise removal in the editor won't be as effective at detecting what is noise."
The macro images involved can be seen here.
https://www.flickr.com/photos/terry-m_flickrphotos/albums/72157670989263398 The extreme close ups of the Hover Fly were the problem images.
I recently upgraded my Canon 600D for an 80D which has many more pixels and therefore could be more susceptible to noise. The reviews were good in this respect and after checking a number of my own images with ISO values from 200 to 1600, all looked good and QU Refine had no problem in subtly removing any noise there was.
My problem macro shots were probably due to being a little under exposed and Raw Refine had to be pushed more than usual in the shadow areas.
Terry