Gazania: visible and UV-370nm images

A Gazania photographed in visible light - left (CT=6500K) and a UV LED source - right (370nm, 3W, 3mm UG2 filter). This is not a UV image of the flower in the conventional sense of a 'bee's-eye view' since the camera sees almost none of the UV light but rather a combination of fluorescent signals.

The UG2 filter blocks essentially all the visible light from the LED and so the yellow colour is presumably excited by whitish fluorescence from within or behind the petal being subsequently coloured by the petal pigment. The blue is presumably reflected LED light within the UV passband of the UG2. [Actually, it cannot be so. I checked by photographing directly the LED through the UG2 filter and all you see is a faint pink light that is recorded through the red-leaks in all three of the Bayer mask colour filters on the camera CMOS detector. I think this blue must actually be blue fluorescence. See:
www.flickr.com/photos/bob_81667/8109134349/ ]

The small bright specks are pollen grains and the bright, elongated patches on two of the petals appar to have been the result of damage caused by the grazing of a couple of light brown winged insects on the back of the flower.

It does look a bit like an illuminated landing pad for spacecraft on a distant, dark planet. But this is an interesting image to try and interpret in terms of physical mechanisms.

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