Today in 2020 more shots of that long blooming spring flower Apache beggarticks - Bidens ferulifolia in reflected ultraviolet photography. All shots were done at f8 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, as well as my deeper UV filters and the IDAS 330nm filter. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was my UV enhanced Xenon flash.
[click on image to see a larger one]
Reflected deep UV with IDAS fiter (300-380nm, peak 330nm):
Reflected deeper UV (290-340nm, peak approx. 320nm):
Quadriptych (details) of human vision, UV, deep and deeper UV (left to right, top to bottom):
Bidens has a strong visible UV pattern, its petal tips are UV bright around 365nm, its center is quite UV dark, so this gets quite nicely visible, also in deep and deeper reflected UV photography.
I have written about Bidens previously HERE
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