Today reflected ultraviolet photography shots using an old achromatic quartz fluorite lens, that I have rescued from an older spectrometer system also using my "work horse" UV filter, the Baader-U filter (approx. 320-395nm, peak approx. 350nm). Light source was sunlight. All shots were done with variated aperture settings (+1 stop difference per image) to show that influence.
[click on image to see a larger one]
Quadriptych form for better comparison.
Zinnia haageana flower:
Sanvitalia procumbens flower:
Not that bad, especially since it has a very small focus shift of only about 1/2mm when shooting macro. That added telecompressor CaF2 lens of about 100mm speeds it up considerably, still allowing a very convenient working distance. The variable aperture allows to control the amount of softness that lens has, allowing for "artsy" shots.And of course it transmits flat beyond 300nm.
Stay tuned, more will follow on that fascinating subject...
More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos