Post processing part 3 – Nice skin
Posted by judycabbages on 2009-03-29
I have no order for doing post processing – it is simply driven by whatever catches my eye. But I typically start with skin since that is usually such a large area of the photo. I create a layer group, rename it to “skin” and place all the skin post processing in layers within this new group.
Create a skin layer group
Spots
Everyone has spots or small skin blemishes. The good news is that they are gone in a few days, the bad news is that I don’t have a few days to wait, so I correct them.
I create a new layer, rename it “spots” (I could perhaps call it the slightly less bad sounding “blemishes” but I am such a lazy typist :) and make sure it is in the “skin” layer group.
Create a spots layer
With the new “spots” layer selected, use the three healing tools. Make sure that “Sample all layers” option is checked so that the healing tool will heal the background image, but place the alteration on the “spots” layer (but I haven’t completely figured this important bit out!). I try not to over do it – I want the person to still look human and not like a porcelain doll. Apart from skin, I also correct things such a maybe a stray hair, distracting clothing glint (zips are bad for this) and lips.
Use the healing tools
Blue channel softlight blur
I had been applying a very similar process but just using greyscale until bassqee suggested Iuse the blue channel – what a great improvement! This is probably the most complex operation. It also has the one greatest effects on the image, particularly in shadowing and colour.
I start out by making a selection of the skin – avoid anything that you want to keep pin sharp such as eyes and eyebrows. For beards, sometimes I keep it out of this selection to keep it sharp, and sometimes I include it in – I have no rules on when or why, just what ever looks better to me at the time. Once I’ve made the selection, I save it (Shift+Ctrl+N, menu Select, Save Selection…) because it will needed again soon. Because I’m not imaginative at all, I named the saved selection “skin”.
Select the skin
Then I feather the selection (Sift+F6, menu Select, Modify, feather…) to something reasonably large so that the transition from unprocessed to processed skin is not (very) obvious. In this photo, I used 20px. I save the selection before any feathering so that if necessary, I can later apply a different feathering to reloaded unfeathered selection.
I create a new layer in the “skin” layer group and name it “skin” (see, no imagination). It is important now to highlight the “background” layer to make it the source of what I do next. Switch over the Channels tab and select the Blue channel, copy it (Ctrl-C), switch back to the Layers tab, select the new and empty “skin” and paste the blue channel into it (Ctrl-V). This will create a grey mask of the selected skin over the person.
Copy and pase the blue channel
But wait! There’s a problem. The mask is a copy of the blue colour that is in the “Background” layer, which means that any blemishes corrected on the”spots”, are also in this mask! To fix this, just do the steps again but for the “spots” layer – create a new layer above (this is important) the “skin” layer, select the “spots” layer, copy the blue channel into the new layer, finally merge this new layer and the “skin” layer. It sounds worse than it is, trust me.
I select the skin layer and blur it a lot (menu Filter, Blue, Gaussian Blur…) so that all detail is lost and only the general shape and shading remain. I used 20px here and probably should have gone quite a bit higher, 30px looks better.
Blur the mask
Finally, change the blending mode, “Soft Light” is usually best but for a more edgy look, “Hard Light”.The other modes give very freaky effects. I also adjust the opacity to lower the effect if it is a bit overwhelming and doesn’t look good.In this case, I left it at 100%.
Set the blending mode and opacity
Try toggling the “skin” layer on and off (click the little eyeball just to the left of the layer) to clearly see what effect this layer has on the image. The most obvious thing is some increased shadow definition and some very very gentle skin smoothing, but now there is a slightly yucky yellow cast!
Warming
To correct the slight yellowing, I add a warming filter. To add a warming filter, select “Create new fill or adjustment layer” (there are a few ways of doing this but I use the popup menu from the bottom of the layers tab), and chose “Photo Filter…”. Rename the new layer to “warm skin”.
Add a warming adjustment layer
The small downward pointing arrow in the icons for the layer indicate that the effect will only affect image in the layer below, which is what I want – I only want to warm the skin and not the whole image. The “Clip to layer below” switch (indicated above) on the Adjust tab for the layer toggles this option. Another way to restrict the warming layer to only the use would be to create a layer mask using the handily saved “skin” selection.
And that is it for the skin!
Post process series
Post processing part 1 – What post processing?
Post processing part 2 – The shot
Post processing part 3 – Nice skin
Post processing part 4 – Dazzling eyes
Post processing part 5 – Brilliant hair
Post processing part 6 – Cool clothes (soon)
Post processing part 7 – Final tweaks (soon)
