Thanks for the excellent fog photo references Rutra.

To me they show that fog in a close-up, like my scene required, is pretty much non-existent. Real close-up fog is a contradiction in terms. It's at most a thin haze - undifferentiated, even and not in the foreground.

So, I had to make imaginary fog - the kind Hollywood and stage shows do with dry ice and blowers. The horror movie type fog.

No doubt my imaginary fog could be improved a lot, but I don't think it could ever be photo-realistic, as your references demonstrate. That scene required "artistic license", rather than "photo-realism". These things are trade-offs which visual communicators have to decide on and go with.