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[UV/Vis] Tree trunk in reflected UV and Visible Green

Just some introductory shots. My primary interest is insect [especially predatory] vision, so I've been playing with various combos of filters - primarily the Baader U and Green filters. Just some shots from today - winter is rough. I just picked up some xume magnetic filter ring adapters - wonderful! I've been testing a full spectrum Panasonic G1 - so far, so good. These are pretty much straight out of the camera w/custom white balance - I have some processing work to do.


UV
P1010440.JPG


Green
P1010441.JPG
 

Asher Kelman

OPF Owner/Editor-in-Chief
Phillip,

What theoretically are the differences you'd hoped for. The first has some tiny islands of magenta and the second the bark and a central layer are green. do you have any idea why that should be so?

Asher
 
I normally try to shoot UV, Blue, Green and sometimes Red - then combine in photoshop in various levels in an attempt to access/recreate various spectral reflectance. I actually had nothing in mind here - the trunk was an even dull brown in 'normal' visible. The purple in the UV shot was Lichen - common, expected result. I was actually quite surprised by magenta in the green filtered shot - so, why did the knots looked like that - sap closer to the surface? I often go out and shoot anything/everything just to see what pops out - I'm often surprised!

My quandry is that it is fairly easy to determine the relative reflectance of insects, but not so easy to determine the visual spectra of predatory birds and insects. Not everything has an evolutionary purpose.
 

Asher Kelman

OPF Owner/Editor-in-Chief
My quandry is that it is fairly easy to determine the relative reflectance of insects, but not so easy to determine the visual spectra of predatory birds and insects. Not everything has an evolutionary purpose.

Phillip,

Don't you need to illuminate prey or a path for the the animals to find their way, or not, or else use electrodes in the brain to find out what light triggers a signal?

Asher
 
Thats one way, there are others, but none of them are easy. I've been looking at several Buprestis spp. [Jewel Beetle] - many are very colorful and are often preyed upon by Cerceris fumipennis [burrowing wasp]. The first thing that became clear - the obvious 'visible' colorful markings disappear in UV - mostly uniformly dark [not very reflective]. Colorful markings for sexual attraction? Lots of questions - just getting started.
 

Asher Kelman

OPF Owner/Editor-in-Chief
Thats one way, there are others, but none of them are easy. I've been looking at several Buprestis spp. [Jewel Beetle] - many are very colorful and are often preyed upon by Cerceris fumipennis [burrowing wasp]. The first thing that became clear - the obvious 'visible' colorful markings disappear in UV - mostly uniformly dark [not very reflective]. Colorful markings for sexual attraction? Lots of questions - just getting started.

Phillip,

Are you a graduate student or research assistant in a University with laboratory resources or is this your hobby?

Asher
 
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