Hi all. Ta for the comments. MacGyver, I agree, but I'm not too sure what too add to help with the scale. In all fairness to me, this was more a mess about with the crater shader, cause I hadn't used it before... that's my excuse, & I'm sticking to it

Anyway, here is a new version, in the dark with some lava at the bottom. It didn't have as much effect on the smoke as I thought so I may do some more to this...
Miles