During the initial testing of the new LAOWA 100mm f/2.8 "Ultra-Micro CA-Dreamer" lens (the blurb is the maker's), I did just for fun a few captures in UV.
The result simply was stunning in terms of image sharpness. This must be one of the sharpest optics I ever used in UV. The UV false colours are of course way off the expected chart, but pleasant nonetheless and bring an aspect of autumnal colours as well.
LAOWA 100mm f/2.8 @f/4.5, 3 sec ISO 100, Nikon D3200 (built-in Baader U)