The "Luminance" noise reduction slider is by default at 50, even for low ISO files. I noticed that, if I set it to 0, expecting the image to appear more sharpened, the image ended up less sharpened - or rather, upon further inspection, less contrasty (less local contrast).
Does C1 increase local contrast "under the hood" when the luminosity noise suppression is increased?
Anyway, I find that with luminosity noise reduction at 0 instead of 50, and the default sharpening settings, images look more natural: with luminosity noise reduction at 50, they are often exhibit too much local contrast to my taste.
Does anyone see the same thing (I use a D700)?