Today shots of a spring flower, a Field Buttercup - Ranunculus acris in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as my XBV6 filter for simulating bee vision. Lens was a CERCO 94mm quartz fluorite lens. Light source was sunlight. All shots were done at about f5.6.
This well known plant has a very unique feature, it has very reflective petals which are able to light up your skin if held beneath. I make this visible here in human vision, ultraviolet and simulated bee vision.
[click on image to see a larger one]
Triptych of human vision, UV and simulated bee vision showing strong 45 degree reflection. Undersides are very UV dark, just petal inside reflect strongly UV (left to right):
Triptych of human vision, UV and simulated bee vision (left to right) showing how much this flower stands out for its pollinators against the background :
This Ranunculus flower indeed shows a quite unique feature, very strong specular highlights and directional reflection under a 45 degree angle. It also has a very specific UV bulls eye pattern, its petals are bright in UV around 365nm, but its center is very UV dark and all this gets nicely visible, also in simulated bee vision.
There is a very interesting scientific paper about that 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