Many thanks both of you, but errm... @Irish: I want to learn how to do it manually, not by adjusting presets. I'm quite happy adjusting presets once I know how they work, but they usually introduce too many new variables for me to cope with. I'd prefer to learn what the various settings do, even if that takes longer. Later, I'll get into fiddling with presets (although I certainly admit they give a good starting point). @jc: I want to only affect the sky. I certainly will be playing with focal length etc (in fact I already have - that scene is not at default FL, IIRC), but I like the scale/truncation as it is. (I am familiar with focal length from many years doing photography.) But, as I said, I only want to affect the sky. I'll deal with the other details later:-)) I've spent several hours in the atmosphere lab trying to get the sky to look more realistic. It needs to be darker at the top (and possibly more blue), but I haven't yet found the specific bit(s) that I need to fiddle with. But thanks anyway:-) Cheers, Diolma