That's incredible attention to detail and construction of the face. I'd like to read your process of colour selection for the face, that skin tone's superb, even if it's a recreation of another photo.
Okay, time to give away the secret (it will be less amazing now, haha, but...)
Obviously I did
n't use the clone brush, what would be the point in that? But I did use the eye dropper to make my initial colour selection for the skin and lips. I believe I used the eye dropper only four times. Once for the mask colour, once for the skin, and twice for the lips.
Once I have the colour and shape (the initial grey blob) I use an overlay brush with colour set to black or white to do the shading. This might be the same as using the dodge and burn brushes. I'll do a rough estimate of the shading first then I will zoom in and start detailing.
In GIMP this is how the paintbrush parameters affect the way the brush works in overlay mode:
Brush Colour - Black: Pixels in the image darken (value is lowered equally across RGB) but hue remains nearly constant. Saturation tends to change a bit.
Brush Colour - White: Does the same as black but pixels in the image become lighte (value is increased).
Brush Colour - Any other: Depending on the value (RGB) of the color you select it will either lighten or darken the pixels in the image. Also, the pixels affect by the brush will begin to have their hue become more like the brush color with each successive click.
Brush Opacity - How strongly the effects of the brush will be applied in one click. I usually have this set low within 5 to 20.
I don't know if this is 100% accurate, but this seems correct. Would you know if dodge and burn do the same thing?
On to detailing. When I detail I'm using the healing brush, smudging, the paintbrush set to overlay, and rarely the blur brush. I zoom in on the picture, do work, zoom out, compare images, zoom in and compare images, do more work, and repeat. I have noticed that initial colour you start with before shading doesn't have to be
too accurate, after I detail it tends to look correct. If the colors off you can always set the paintbrush to colour mode and go over certain areas of the image with a different colour. (I didn't do that with this picture.)
You also start to develop an eye for how pixels should look when you zoom in on a photo. The pixels form a mesh that flows. The value of a pixel may change from one area the image to another, but you tend to always see some sort of anti-aliasing (if that's the right term) around the pixels. They flow into each other.
The things is I have to reference another image. I can't barely draw anything without a reference. Also note that I had to keep everything the exact dimensions of the image I used. I couldn't make it look as good if I went of scale, well I might be able to make it look decent I did a pencil drawing of a portrait of myself once, using only a mirror, pencil, and paper. It wasn't too bad.
I have very little formal art training, so I always reference some image and just go off that I usually can't make many changes to the my creation from the reference or else it starts to look wrong.
So I still wonder, is it actually an impressive feat? Or just something anyone could do given they had enough time?