Which came first, Pre-Sharpen or Noise Reduction?

What is the best initial Nik workflow order?

I go back and forth when working with the Google Nik plugins and my workflow in Adobe Photoshop or Lightroom. Should I use the pre-sharpener first, as the Google Nik Workflow suggests, or should I use DFine noise reduction first, as others and myself believe to make more sense? Does it make any difference?

It seems to me that if there is noise present in an image and you use the pre-sharpener first, you'll be sharpening the noise, which seems like it would then be more difficult to apply the noise reduction. It seems like the blurring would have to be greater.

Nik's workflow doesn't really offer any reasoning for applying the pre-sharpener first, but it makes sense to me that it would be easier to detect where to sharpen before any noise reduction basically blurred the image to a small extent.

I decided to try both approaches to see if I could find any differences.

Experimenting

I used one of my photos from Bryce Canyon National Park that has some shadows that likely need a touch of noise reduction. The shot was taken at sunset where most of the hoo doo area was in shadow but, as you can see, the distance is still in sunlight. I really wanted to sharpen this image to add some more detail.

I opened this image in Adobe Camera Raw (ACR) to import it in to Photoshop as a smart object. I did not apply any noise reduction or sharpening in ACR. By opening it as a smart object I was able to use the same image and to modify the Nik processing.

You should be able to click on these images to get the full size version. Note that they are JPEGs so there is additional processing beyond what I could see in Photoshop.

Bryce Canyon NP - Noise Reduction followed by Pre-Sharpener

Bryce Canyon NP - Pre-Sharpener followed by Noise Reduction

In the first image I applied noise reduction first and then the pre-sharpening. In the second image I applied the pre-sharpener first, followed by the noise reduction. I didn't do any other processing - I wanted to see what the difference is between the two approaches, if any. I used the Nik DFine noise reduction at it's default settings in both cases.

For the pre-sharpener, I set the Sharpen Areas -  Sharpen Lines balance towards Sharpen Lines, with the slider basically above the "N" in the word "Normal" below the slider. Note that when you use the Nik plugins without closing Photoshop in between uses, they open with the previous settings applied. When I switched the order (by deleting the filters in Photoshop), the pre-sharpener opened up with exactly the same setting applied. Everything else was set to the default settings.

Conclusion

If you download both of these images and open each one in a preview panel (I don't know how to do this on a Mac), you can set both preview panels the same by clicking Windows Key + [Left / Right] Arrow Key to get them side by side on your monitor. Then click the Actual Size button on both windows to set the images to 100% and to display the same area of the image.

In my opinion, there is not a lot of difference. It looks to me like there is pretty much identical sharpness in the details, which is good. The little difference that I see is that there are some red pixels creating a color noise artifact in the shadows that appear more defined and sharper in the version where pre-sharpening was applied first. In other words, from this experiment on this image, it appears as though it is (barely) better to do the noise reduction first.