UV Nikkor 105mm and polarizer

[Dr Klaus Schmitt]

Here today a bit about using the UV-Nikkor 105mm in polarized light, using a PHLOX - Rockfoil flower
and a deep reaching (up to 320nm) circular polarizer in front of a Baader UV filter (320-390nm), so this
is reflecetd UV btw.

Phlox flower in M-mode i.e. non exposure compensated:



Phlox flower in A-mode i.e. exposure compensated:

[Birna Rørslett]

Interesting. So, basically, the surrounding foliage and stems change more than the flower itself?

[Dr Klaus Schmitt]

Interesting. So, basically, the surrounding foliage and stems change more than the flower itself?

In this case yes. Just talked to a friend and Professor for insect sensory perception and bees on the
outer rim of their eyes have sensors for polarization he said. So I am looking forward to highly
reflective flowers like the inside of tulips etc. There should be some interesting things to see! Just
all parks here are closed, so no access...

[Dr Klaus Schmitt]

Btw. man-made structures do show quite some polarizing effects...



This was shot using a special Zeiss Jena UV-Polarizer which works down to 300nm (but is this case there is only down to 340-350nm visible)

[MEPER]

Regarding the blue flower I like the first image most where the flower reach the darkest blue color.
Possible to post that as a still image?

[Erik Lund]

Interesting finding

[Dr Klaus Schmitt]

Regarding the blue flower I like the first image most where the flower reach the darkest blue color.
Possible to post that as a still image?

Here...

[MEPER]

Thank you!
It is a nice blue color.

[dickb]

Was the light on the background constant when you took the Phlox series? The variation in brightness in the background reminds me of what you would see when sunlight filters through leaves on a windy day.

[Dr Klaus Schmitt]

Interesting. So, basically, the surrounding foliage and stems change more than the flower itself?

Here another example (white Saxifraga flowers), which shows the predicted effect my friend told me about:

Reflected polarized UV, using a 365nm UV LED:




Reflected polarized UV, only sunlight:

[Jack Dahlgren]

I'm not quite sure what behavior is being displayed and whether it is different with UV rather than the rest of the spectrum.
One would expect that the same sort of polarized reflection which obeys Brewster's angle.

https://en.wikipedia.org/wiki/Brewster%27s_angle

While index of refraction is different for UV, the principle is the same.

What should I be looking for in these images?

[Dr Klaus Schmitt]

Was the light on the background constant when you took the Phlox series? The variation in brightness in the background reminds me of what you would see when sunlight filters through leaves on a windy day.

Yes it was Dick, it only took short to take those 8 shots...

[Toby]

Very nice!

[Dr Klaus Schmitt]

Very nice!

Thanks Toby!

[Alaun]

Very nice Klaus.

Did you test the old Zeiss Bernotars as well?

(D810 full spectrum, UV Nikkor 105mm, Baader U, Zeiss Bernotar)