Dan, I don't think that the f/1.8 45 likes being stopped down as far as that! There appears to be a lot of diffraction softening in your pretty photo.
Some lenses (and subjects) cope with small apertures OK. My FTs 14-54 MkII shows quite distinctive diffraction softening at f/7.1 with some subjects, yet appears tack sharp with others at f/11 or even smaller.
OTOH, my 12-100 is happy as Larry at f/13. But not at f/16 ...
Those who categorically state that diffraction softening commences at such and such f/stop values for lenses for specific formats are demonstrably wrong, IMNSHO. It's different from lens to lens IME.