[click on image to see a larger one]
Visible light image:
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UV image using Baader-U filter (approx. 320-395nm, effective peak approx. 375nm):
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Simulated bee vision image using experimental XBV filter:
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This iris has a UV pattern, its petal "lips" are UV dark, wheras the rest of the petals reflect stronger around 380nm. This older quartz fluorite lens is reproducing this quite well and all that gets nicely visible.
Stay tuned, more will follow on that fascinating subject...