Frequency Separation, Noise and USM Local Contrast

In this final chapter, Karl delves further into Frequency Separation, noise and local contrast control.

He demonstrates how these can be used in your skin and beauty retouching workflow as he goes over the final steps of his retouch, showing you how to separate contrast texture from the overall tone and explaining the advantages of this technique.

He also shares further advice for sharpening your images and shares a special tip to speed up your frequency separation workflow.

In this photography class we cover the following:

  • How to use Frequency Separation for retouching
  • The advantages of using Frequency Separation
  • How to smooth skin in Photoshop
  • Using burning and dodging to smooth skin
  • Sharpening images using Unsharp Mask

For additional techniques and further demonstrations on how to retouching skin, please watch our ‘Advanced Photoshop for Photographers’ course.

Please post any questions in the box below.


  1. Karl, I have a question on the Frequency Separation.

    In the past, when I learned to create the High Frequency (Texture) layer, after selecting Apply Image, I select “Subtract” as Blending, and set Scale to “2” and Offset to “128”.

    Can you explain the difference between selecting “Add” vs. “Subtract” Blending when performing Frequency Separation?


    1. Hi DG, the results look exactly the same to me having just tested it, but that’s the first time I’ve tried it using the subtract blend mode, but it only seems to work with your values of Scale 2 and offset 128. The reasons for this I’m not clear on, I would need to consult with Viktor. However if it provides a low frequency layer and a high frequency layer which when combined in Linear Light blend mode look exactly like the original layer then it will provide the information necessary for the retouch.

    1. Hi Chuxi, on your customer home page at the top there is a large panel to contact Sara in customer support or one of the team. Not all of the admin staff are available at weekends though but on weekdays you should get a reply within an hour. Also check your spam folder incase the email response went there. For all technical questions we supply support for each class by using the comments section below the relevant class as you have done here. These comments are checked daily including weekends.

      1. Karl, thank you! Love your style of teaching by the way. You explains things in a way that is very easy to understand. Best wishes.

  2. Hey Karl, i normally use the Surface blur instead of the Gaussian blur, would you recomend better the Gaussian? why?

  3. hi, OK. Ive sorted it out now. I think it was the way I either duplicated the layers or made new layers

  4. Hi Karl,
    Im having trouble with my hf layer. I set up my background layer, made two duplicates, applied the gaussian blur to the lf layer. I then applied the settings for the hf layer and hit ok. all looking good so far but then when I change the hf blend mode to linear light instead of the original image popping up the image just gets too light to see. Whatever am I doing wrong ? Im working alongside your video for frequency separation
    Thank you

      1. Ok, I googled a bit and found that the solution is to put the Scale value in the apply image window to 2. By default it is set to 1. If you change that value it works.

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