What is Frequency Separation?
Frequency separation helps make retouching a portrait easier in Photoshop. Frequency separation works because it allows you to separate the texture of an image from the tone and color. When retouching you can focus on just the texture or the skin beneath it.
It sounds quite complex but in practice it is quite simple. If you want to work with texture, choose the high frequency layer, if you want to work with skin choose the low frequency layer.
