Now that we’ve reduced the noise to an acceptable level without losing too much details, it’s time to bring those details back and sharpen the image to be used as a base source image and for final output.
The ‘base source’ image will be the stage when the image has a proper balance of noise control and details revealed. This source image can now be used for further editing, sharpening, and output adjustments (for various print size or web usage).
We’ll start by merging all the NR changes we’ve made to a new layer by holding CTRL-ALT-SHIFT-E. This creates a new active layer by combining all the visible layers.
Rename this new layer as “Sharpen”. This will be our “detail restoration” layer after our noise reduction workflow.
Notice that I’ve also set the layer opacity to 70%. By setting my layer to 70% BEFORE applying my sharpening values, I will still have the option to INCREASE sharpening after the filter is applied. If I left the layer to 100% opacity before applying my sharpening filter, I can only REDUCE my sharpening amount by adjusting the Opacity value. Starting at 70% gives me an extra 30% sharpening leeway if I need to increase the sharpening value (If you’re working with Smart Filters, then you don’t need to do this anymore).
We’ll be using the High-Pass + blend mode sharpening technique to restore global details for our image. If you’re not familiar with this technique, careful sharpening using the High-Pass filter on a layer with a Blend mode set to Overlay, Soft Light, or Hard Light sharpens only edge details while minimizing color shifts and amplifying noise. You can access the High Pass filter via FILTER >> OTHER >> HIGH PASS.
Pushing the Radius slider to the right increases sharpening. Remember that we’re still working on an image at its native, full-size resolution, so gauge your preview at 50% or 100% view for better accuracy.
For a 10MP image, I usually set the Radius amount between 2-4px. Just enough to see the edges through the filter without creating ugly halos. Click OK if you’re satisfied with the edge details.
Change the Blend mode of this Sharpen layer to Hard Light. You can experiment with Overlay or Soft Light as well. You should see your image returning close to your original image’s details before the noise reduction was performed.
I want to limit my sharpening to mainly the midtones of my image, leaving the deep shadows and bright highlights unsharpened. Oftentimes, the shadow/highlight details do not require that much sharpening anyway, I want to retain as much midtones as I can for future editing and output.
We can restrict the sharpening to be applied on the midtones only by using the Blend-If sliders under the Layer Styles window. Right click on the Sharpen layer and choose Blending Options.
The Layer Styles window opens and look for the Blend If section near the bottom of the window. The Blend If option allows you to apply the layer style on specific light or dark areas in the image. The left part (black) represents the shadows (>= o values), while the right represents the white values (=< 255 values)
Drag the black triangle (shadows) to about 30, then hold the ALT key to split the black triangle, drag the other half of the black triangle to about 100. Do the same with the white triangle, but to the values of 200/155 range. Feel free to use wider/narrower values depending on your image. In this case, all areas between 0-34 and 221-225 are NOT sharpened.
This is now our base source image. Mouseover to see the NR (no sharpening) image versus the sharpened image.
The details are recovered after the noise-reduction phase and the image is ready for further editing, resizing, and sharpening according to its output size (web or print). Now is a good time to save the image file as a PSD, TIFF, or PNG, depending on your preference.
Head over to Part 3 – Output Sharpening.