Retouching portraits with Gimp, adjustment layers and thinking about moving on to Krita or Photoshop
My photographic output is generally well received by models and friends alike, but they are not a very critical bunch so being content with the status quo would be utterly presumptuous from my part. But there is no danger of that, as kaizen is very dear to my heart.
Although I now have a good grasp of basic tools such as various selection implements, levels, curves, noise reduction and sharpening, my retouching skills are still very far from anything serious. Training helps me creep slowly forward, but it has now been a few months since it dawned on me that those skills probably won’t improve much more until I get myself to learn dealing with layers and transparency. Spray painting with the clone brush on the background layer is better than nothing, but a good layered makeup with gaussian blur and assorted masking trickery is what I am really aiming for.
The tool I am missing is called “adjustment layers” : “an adjustment layer typically applies a common effect like brightness or saturation to other layers. However, as the effect is stored in a separate layer, it is easy to try it out and switch between different alternatives, without destroying the original layer. In addition, an adjustment layer can easily be edited, just like a layer mask, so an effect can be applied to just part of the image“.
So I went looking for explanation on how to use adjustment layers. I found Tea Leaves explaining how to use adjustment layers with an example in the context of Photoshop – according to him “it is like having a darkroom notebook that also remembers exactly how to edit your pictures for you. It really is magic“. Matt Greer explains in more detail the benefits of adjustment layers :
“The benefit to using adjustment layers is that no edit is permanent until you flatten the image. You can even save the image with all of its adjustment layers as a Photoshop Document (.psd), and when you reopen it, all the changes you made to the adjustment layers will still be there for you to change back, remove, or alter.
If you were to, for example, edit curves without layers, then go on to change saturation, crop the image, then add vignetting, the only way to go back and change what you did to the curves would be to go back in the history, to when you changed the curve (thus losing all work done since), or start the image editing from scratch.
With adjustment layers, however, so long as that adjustment layer is still there, you can go back and alter the adjustment at any point in the editing process”.
Phong explains how easy it is to add an adjustment layer, and Martin from t-tutorials.com explains their power at further length. So far so good, I’m sold on adjustment layers ! But what about my photo retouching tool of choice, Gimp ?
Gimp lacks adjustment layers and users have been complaining about it for quite a while. Actually I should say that the lack of adjustment layers is an essential part of the classic list of rants against Gimp. Raphael Quinet, Gimp.org webmaster from 2001 to 2004 says : “Adjustment layers will not be in 2.4. This will probably have to wait until the GEGL-ification of GIMP is complete (i.e., GIMP 3.0)“. Raphael even mentions a feature wishlist item about about adjustment layers that has been open as a bug since 2002.
GEGL-ification of GIMP ? That could take a while. There have recently been a few encouraging noises about a revival of GEGL’s development, but by all estimates GEGL still appears on the same horizon where it has stayed there for the last seven years. GEGL is supposed to cure GIMP‘s woes by letting it scale freely in image sizes, number of layers, bit depth, functionnality and anything else you might imagine. GEGL looks very promising and the rumor says that it is rooted in very sound foundations. But in the context of GIMP, GEGL smells like a severe case of second system effect. I am not betting my money on a GEGL-ified GIMP appearing anytime soon. I do believe that GEGL will deliver an awesome next-generation graphical framework, but for GIMP it will be too late.
So where do GIMP refugees run to ? Photoshop is quite expensive, and CS2, its latest incarnation is does not run well in Linux with Wine. But hope is not lost : Krita has had adjustment layers for almost one year. Krita looks like the light at the end of the tunnel, the potential savior also bringing forth the high bit depth colorspaces that will one day enable the full 16 bit workflow that begins with the RAW image files. Krita even already mention adjustment layers in its documentation – that is a very good sign. So for now I am going to take a very close look at Krita and experiment with it with the goal of replacing GIMP in the short term. Adjustment layers alone pushed me to consider migration but with the prospects of a 16 bit workflow on the horizon my motivation is now even stronger.
But with all this talk about tools, let’s not forget to sharpen those retouching skills too. And while retouching let’s not forget about those photographic skills either. Let’s start with this example of bad lighting :
Under bounce flash, the shadows under the cheeks of this particular model are not nice. Next time I’ll try using my brand new pocket studio lighting to get rid of them… And that illustrates that as usual there is more than one way to improve an image. After a whole article of ranting about image manipulation tools I want to conclude by putting them back into perspective : digital hackery will always come second to getting a good exposure.
(Serendip) is the historical Arabo-Persian- form of Sri Lanka, a word with Sanskrit (Pali) origin, naming the island of Singhalese 
(Sinhala dvipa) and kept alive in folk tales and legends of this area.
