Tuesday, July 14, 2009

Blue Bananas?

Well, something interesting and kind of funny today. I read on the net, that scientists in Innsbruck, Austrai and Columbia University, New York have found, that bananas emit blue fluorescence light when radiated with UV light of 365nm, but depending on the degree of ripeness of the banana. This is caused by breaking down of the green chlorophyll and these byproducts accumulate in the peel. So why not try to make that visible, since I have that equipment anyway here for my UV photography...

[click on image to see a larger one]

The bananas as we all know them in visible light:

Now radiated with my 365nm Nichia UV LED and with UV blocking filter in front of the camera lens:

Just looking at the blue channel makes it even more prominently visible:

So obviously bananas do fluorescence and it gets very obvious that the one in front is the ripe one, wheras the one in the back is the green, unripe banana. So have your UV light ready when shopping for bananas next time...!!

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