Retouching and smoothing skin
Originally published in Computer Arts and Creative Bloq. Updated.
There are few better ways to retouch skin than zooming in 100 or 200% and manually correcting bumps and blemishes with dodge and burn. But when you need to work quickly – or when the effect you’re going for is purposefully smooth – techniques such as frequency separation, inverted high-pass and even skin smoothing plug-ins, will always have a place in the retoucher’s arsenal.
First, for a basic retouch, we’re going to use Photoshop’s Healing Brush tool to remove any obvious spots, blemishes and stray hairs. We’re also going to use the Dodge and Burn tools – which enable us to selectively lighten and darken parts of our image – to contour any abrupt shadows, and to go over areas like dark rings underneath eyes.
Many retouchers prefer to use tools like the Healing Brush, Dodge and Burn on their own separate layers, with the Healing Brush set to Sample>Current and Below, and Dodge and Burn being performed on an Overlay or Soft Light layer. I’ve chosen to use both tools together directly on a duplicate of our source image, as we’ll flatten both layers in the second stage anyway.
01 The first step is to create a duplicate of our source image and select the Healing Brush tool. This is an ideal tool for cleaning up any obvious blemishes. I use a small, soft brush, and generally the key is to zoom in, and Opt/Alt+click on small, clean areas of skin, then paint over nearby blemishes or lines of similar tone, avoiding any edges.
02 Next select Photoshop’s Dodge tool, which will let us add light to the shadows. I use a soft brush with a 2% flow to lightly go over unwanted shadows, and to smooth and contour highlight and shadow regions. I like to switch between the Dodge tool and the Healing Brush quite often as, with practice, you’ll find the two can be used quite symbiotically.
03 If you’re happy with the results so far, delete the source image, duplicate our retouched version with Ctrl/Cmd+J and label this layer ‘IHP’. Now, with our IHP layer selected, change the blending mode to Linear Light and Opacity to 50%. Add an Invert adjustment layer, and add it as a clipping mask for our IHP layer by Alt/Opt+clicking between the two layers in the Layers panel.
04 You’ll know if you’ve done everything correctly so far, as we should have a screen of 50% grey. Now, with our IHP layer still selected, select Convert For Smart Filters… from the Filter menu. Now select a High-Pass filter, and increase the radius until we get a smooth, soft image with enough form and structure in the highlights – here we’re using 12-13 pixels.
05 Now select a Gaussian Blur filter. A typical rule of thumb is to have the pixel radius here around a third of the value used on your High-Pass, but adjust it until you get the desired level of pore detail in the skin. Next add a Mask to our IHP layer, and invert it (Ctrl/Cmd+I). Now we can paint the effect in with a white brush, avoiding any edges or specular highlights.
Using masks and changing the Opacity, this technique can be used as subtly or unsubtly as you wish. While it gets a bad rep as a quick, cheap way to smooth skin – leading to many a Photoshop disaster – it’s certainly implementation that dictates results.