I did this project back in the days of Blender 2.64. Then, in the Cycles renderer, neither Hemi Lights nor a Mist Pass were available. This scene is lit by a single light source: a Sun Lamp. The atmospheric perspective effect is made by tinting and blurring the Z Pass.
For this post, I rerendered the landscape at a bigger size - after making the sun lamp brighter and adding the birds. (They are just white spheres pushed and pulled into shape. They look OK, yes? )
The World Background has a navy colour. This helped me get darker shadows but doesn’t make a realistic-looking sky. So the sky is actually a composited Blend Texture.:eyebrowlift:
The landform mesh has been used in several of my landscape projects. It was made with a Terragen 8 bit grey-scale image used to displace a much subdivided plane (in Blender). It has about 68,000 vertices.
The rock material has 4 textures. These were combined in Material Nodes, 2 Noise Textures and 1 Image Texture for a rough pitted look and 1 Magic Texture for the sedimentary colour striations.
By the way, this is a 100% Blender Cycles image. (That is, no further image manipulation was done to it.) It took about 25 minutes to render using 20 samples.
Hope you find this interesting.