Thank you very much, bobbystahr. Looking forward to what you come up with.
luvsmuzik, it is the simply name of the original image I used to create the image I use as a mask shader and a image shader in this scene.
A lot of Photoshop Filters and layering of the original image (a orthographic view of a type writer "kugelkopf") ended up to become the "kugelkopf_00b_s.jpg".
The attached render has Primary Rays of the Atmosphere node disabled.
The dark blue grain comes from the kugelkopf_00b_s.jpg in the Background node,
which gives the Atmo the blue-ish grainy tone. The image is sized down a lot to get the grainy effect.
The large dark shadows on the terrain are also coming from the kugelkopf_00b_s.jpg image.
This time the image is enlarged and used as a mask in the Base Colour node.
There is also some luminosity with different colours used in the image nodes.
Is that it? Or did I miss something...
CHeers, Klaus