This is another technique for avoiding noise and color shifts when sharpening, but this one makes use of Layers and Blend Modes. The method shown here is a cross between a Stechnique that I learned from Chicago-based retoucher David Cuerdon, and one from Jim DiVitale, in one of his columns for Photoshop User magazine.
Open the photo you want to sharpen using this technique. Duplicate the Background layer by pressing Command-J (PC: Control-J).
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Change the Blend Mode of this duplicate layer from Normal to Luminosity (as shown).
Apply the ...