Thursday, July 23, 2026

Black-eyed Susan - Rudbeckia hirta in reflected ultraviolet photography and simulated bee and butterfly vision XIX

Today more shots of that beautiful flower, originating from the USA Prairie, here today again that commercially sold hybrid of a Black-eyed Susan - Rudbeckia hirta (possibly R. hirta x R. fulgida) in reflected ultraviolet photography using different filters aside from the Baader-U filter, but different ones today for simulated bee and butterfly vision but also part of my XBV filter set. All shots were done at f8-f11 on my balcony. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was direct sunlight. 

PS: These other filters (filter stacks actually) I used have partially corroded over time, so I had to polish them using finest Cerium-Oxide powder. I made some slurry with that using filtered water, then polished the filter glasses with that using a very soft cloth and small circular movements, then rinsed them clean and dried them. So these images hopefully prove that this was successfully done....I think so.

[click on image to see a larger one]

Human vision:
 

Reflected ultraviolet (UV - false color):
 

Simulated butterfly vision:
 

Simulated bee vision:
 

Quadriptych of human vision, ultraviolet, simulated bee and butterfly vision (left to right, top to bottom):
 

This flower shows a very prominent UV bullseye pattern, as its petal tips are very UV bright (around 365nm) and its center is very UV dark, and all this gets nicely visible, also in simulated bee and butterfly vision.

I have previously written about that flower 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

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