In the segments of the LR4 tutorial that deal with sharpening and noise reduction, Jeff adjusts the sharpening first, even with an ISO 12,800 image. He then works with the noise reduction sliders, and then goes back to tweak the sharpening adjustments.
I have found it difficult to evaluate the sharpening settings until I have first done the best balance of the noise controls, with sharpening turned off completely. I am careful to avoid that plastic look that comes from too much Luminance NR, and bring back as much detail and contrast as possible without making the image look noisy again. Then I go to the sharpening controls, adjusting the radius large enough to not sharpen the noise, and raising the amount slider just below the point where stuff starts looking crunchy at 1:1. I then move the Sharpening detail slider and masking to taste, and tweak all the sharpening sliders.
Next, I try tweaking the noise sliders to squeeze more detail if possible, and with some images I add a bit of grain.
Again, it seems easier to me to start no with sharpening, isolate the actual noise, take care of the real noise as best as possible, then do the sharpening.
Am I missing something with this approach? Is one way more effective than the other, or is it just a matter of personal preference?
I also am not sure whether I can get better results by doing the NR before the opening the shadows, or doing my big tonal moves before working on noise reduction. But it seems that knocking out the noise first and then brightening the shadows ends up at least as clean of noise.