I have to confess a bit of a cheat. I took lots of pictures on this this being my favourite composition by far. But when I uploaded it, to my horror and in spite of the tripod and remote shutter, there was some camera shake. So I'm thinking it's time I learned how to use the mirror lock-up. In the meantime, rather than discard this photo I added another layer with some gaussian blur, then reduced the opacity to give a slight diffused look. I have never tried this on a night shot before, but I have to say I was quite pleased with the effect.

Original Photo