Sunday, April 21, 2013

Apache beggarticks - Bidens ferulifolia in reflected UV ultraviolet photography

Today about a quite well known spring flower, Bidens ferulifolia or commenly named Apache beggarticks in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter. Lens was a CERCO 94mm quartz fluorite lens. Light source was Xenon light. All shots were done at about f5.6. I have written about that flower last year and also measured its special UV reflection using my spectrophotometer as well as I have shown it in various spectral bands and simulated butterfly and bee vision.

[click on image to see a larger one]

Visible light image:

UV image using Baader-U filter (approx. 320-395nm, effective peak approx. 375nm):

Bidens has quite a prominent UV "bullseye" pattern that peaks around 365nm on the petal tips, buts its center is very UV dark and this gets nicely visible.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site