One of the things about walking around the place all the time is you happen across more things. Lastnight on the way back from the shops I observed that it was starting to sprinkle very lightly delicate ice crystals which would be what I'd call "dew" if it wasn't freezing. Looking around me I could see evidence of light pillar formations.
So I headed for the river and found this as the best shot:
Sadly I only happened to have my phone not my "proper camera" and thus was only able to get this image. Still, better than none :-)
This is something which I've read about but never (till now) witnessed ... fantastic.