Wednesday, July 18, 2007

On Fluorescence Photography

Taking shots of flowers esp. close up I noticed that pollen seems to somewhat lighten up. So I made a test using a UV flash, but had a UV-blocking filter (Baader UV/IR Cut filter) in front of my taking macro lens. It gets quite obvious, that at least some flowers use the energy in UV light to enhance the brightness of their pollen to make it more visible to insects - their pollinators.

Here some macro shots I did using the 2" Baader-U for the UV shots and 2" Baader UV/IR Cut filter for UV-Fluorescence. The fluorescent pollen get clearly visible.

Some examples for that follow. Here the visual shot first:
(click on images to get larger (1024 pix) images)




The UV shot however looks very different and since the pollen looks quite dark, this means that the UV energy gets absorbed by the pollen. So where does it go to? It gets transformed (maybe just partly) into visual light.




So if we now use the UV cut filter for that African Daisy, this is made visible:




So this is another trick what flowers do to attract pollinators. Here an even closer macro shot of that:




Another example of a multitude of ideas nature has applied.

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>