IMAGEs by DEN - Tutorial

The original image was taken from the DP Review Retouching forum here where the poster requested assistance to mellow out the deep shadows. While a simple mask of the shadow and lower mid-tones used with Color Curves HSV,V brightening would be the simpliest means to accomplish this, a contrast mask method was used in combination with the Composite-SoftLight transform.

Mask1 is a 'darkening' gamma curve [curve = [0,0], [50,20], [100,100]] mask image that isolates the image's strong highlights with a fairly strong darkening gradient for mid-tones and shadows.

Mask2 is Mask1 used as the Input image and Mask of the Filter transform, then 'Subtractive'-ly filtered with an inverted [black and white are interchanged] and slightly blurred [Blur = 25] version of itself to maintain the highlight details... [See the main tutorial, Step1 and Step2]... Notice that Mask2 has good detail where the original image highlights occur but is blurred elsewhere... this provides the gradients so that the tranformed image will not have objectionable halos/auras...

Mask2's mid-tone [50% gray] is also selected to be approximately the same tone value of the pool water... this is important when using the SoftLight filter...

The SoftLight filter blending is limited to the white/light gray areas of Mask2 by the Mask1 slider amounts where black=100% and white=0%. The SoftLight filter lightens where the Overlay image, Mask2, is greater than a 50% tone or 128.