[click on image to see a larger one]
Triptych (left to right): Human vison, reflected UV (longer wave), reflected UV (Baader-U filter):
Diptych (left to right): closeup Human vison, reflected UV(Baader-U filter):
Triptych (left to right): Human vison polarization 0 degrees, rotated 45 degrees, 90 degrees:
This attractive bird has iridescent feathers with a metallic green and blue shine maximized under a 45 degree reflection angle, however it also reflects UV quite well peaking at around 365nm (left) and to some lesser amount 385nm (right), invisible to us humans, and all this gets nicely visible.
Stay tuned, more will follow on that fascinating subject...