thank you all for the appreciation
the background images were indeed created with terragen, a great program, but using it gives you a real headache. On top of that, the renderer is slow as a glacier...
I used a Canon Powershot G2 to make the photos of the model, with a north-facing window as a soft backlight. Composing + color correction was done in Photoshop (of course)
sorry, unsf, I can't render larger backgrounds, so the pics are as big as it gets for now.
-i-