Anamorphotic UV

After the successful wide angle shots, now to the panoramic view. No, not stitching UV shots, that would be too easy, let's try some anamorphotic UV shots.

This was shot at our famous park Hermannshof, Weinheim. Some people where sitting there, resting and talking and enjoying the last rays of that beautiful spring day before the park closed. After they left, it felt as if their energy was still present and I took my shots using that 1.5x anamorphic setup I tried out that day. It was just very pieceful and quiet and this is what I wanted to seize in my shots.

Now as usual first the visual anamorphotic shot:



and this the UV shot [catched some flare on the left]:



and the UV remapped into the visual image as blue:



So, that seems to work, I need to do more like that!

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

Bumble Bee vs.Mexican Zinnia II - spectrometric tests

Mexican Zinnias ("Creeping Zinnia", Sanvitalia procumbens) are quite fascinating little flowers, since they sport a very prominent UV pattern which can't be seen with the bare eye.

This is the visual appearance  [click on image to see it larger]



whereas in UV the flower shows that prominent pattern (like a heli landing platform for bees?)



Now I was curious to find out what the spectrometric reflection response would be, since that pattern must also show there. I used a Xenon full spectrum light source, an USB2000 UV-NIR spectrophotometer and a suitable fiber optic UV-NIR reflection probe.



The light pink curve shows the response of the flower center, not very strong, just reaching about 10% in the visual range and no UV response [for the sake of simplicity I will not comment on the NIR responses for now, this had to do with the used white reflection normal]. The petals however show something different. The ground of the petal (which appears dark in UV) only shows quite a strong visible response in the in the 500nm region and above (green curve), whereas the petal tip (which appears bright in UV) indeed shows quite some strong UV (and blue) reflectance between 330....430nm (dark pink curve) with a maximum at about 360nm. Interesting since one of the receptors have its maximum at about 340nm (300...400nm). But also the visible response of the petal tip is some 15% stronger than the base! For comparison I also recorded the green leaf response which is shown as the light blue curve, much weaker, only reaching a bit more than 25% in the green.

Now what's that violet curve now? The reflection of a white Bumble Bee "rear end". Remember what I showed a few days ago? This is the sythesized bee vision version of a bumble bee sitting on a Mexican Zinnia flower with a prominent UV pattern.



Interesting how that Bumble Bee's (Bombus terrestris) abdomen reflection pattern evenly covers the whole spectrum, but exactly starting at the UV maximum of 360nm of that petal tip up to deep into NIR. More research has to be done on that, it can't be just coincidence, or as Einstein put it, "nature does not play dice"....

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

Simulated Bee Vision IV - Buttercup (Caltha palustris)

Today it is again about Bee Vision. The buttercups are in full blossom here and these flowers show some very prominent UV pattern which is completely invisible to the eye, so I took some shots to demonstrate that:

These first two images are the visual



and the reflected ultraviolet (310 ... 390nm) shot:




This following image now combines the visible and UV shot into a synthesized "Bee Vision Image" and  is the non-linear color mapping into our human color space. UV, which a bee can see is compressed into our visible spectrum as blue, at the same time the red, a bee can't see, is suppressed:



This, of course, is just my personal representation of what I believe respresents what a bee may see (aside from the aspect of a completely different optical apparatus of course...), transformed into our human color space.

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

Very Wide for UV II

Now a few infinity shots on a somewhat sunny but cloudy day using that older ca. 25mm lens (equiv.); the camera was a Nikon D70 @ ISO400.

Visible image first:



Now the UV image:



To show how well the UV image matches the visual shot, I use my remapping technique:



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

Very Wide for UV

I always wanted a decent wide angle lens for UV, so here is a first result with an older ca. 25mm lens (equiv.)

The shots were done outside on a somewhat sunny day, the camera was a Nikon D70 @ ISO400.

Visible image first:



Now the UV image:



And the "bee vision" version of that, with UV remapped into the visual image as blue:



I hope you liked the first results, very exciting!

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

Pinhole for UV II (infinity)? ... not for me

Now a second pinhole VIS + UV test, at infinity now. I used a laser drilled very fine brass pinhole with f180 and one with f240. Camera was a Nikon D70 @ ISO400.

Visible image using the f180 pinhole first, unadjusted except for size, exposure about 1/4 sec:



Now the f180 UV image (whitebalanced), exposure about 30sec, but enhanced by 100% lightness i.e. like 60sec exposure:



Visible image for the f240 pinhole, unadjusted except for size, exposure about 1/4 sec:



Now the f240 UV image (whitebalanced), exposure about 30sec, but enhanced by 100% lightness i.e. like 60sec exposure:



So and the conclusion now? The f240 is somewhat sharper, but still, no pinhole for UV for me, also not for infinity or landscape 
work. As said before, maybe for artistic landscape work. But it works very 
well to show that the camera sensor needs urgent cleaning!

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

Pinhole for UV? ...not for me

I have been told that UV photography could be done using pinholes. Now let's try that out and see if the results could be compared to the ones using special lenses....

The following two shots were done in darkness using no special filter and my Nichia 365nm UV Led lamp/flash for the UV exposure and tungsten cold light for the visible shot. I used a laser drilled very fine brass pinhole with about f180. Camera was a Nikon D70. Visible image first, unadjusted except for size, exposure about 1/6 sec @ ISO400:




Now the UV image, exposure about 4sec @ ISO400:



So and the conclusion? No pinhole for UV, at least not for my work which needs to resolve very fine details. Artistic landscape work might be a different, maybe possible area, though.

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

Bumble Bee on Mexican Zinnia

Today just one image I wanted to share, a Bumble Bee on a Mexican Zinnia (?) flower - how boring? Not really, since both exhibit their UV patterns; have a look....

Also these two shots were done using extention tubes and a Baader 2" U-filter for the UV shot using my Nichia 365nm UV Led lamp/flash. Now here they come assembled into one image and the UV image somewhat matched in color to enhance the UV pattern:



Notice the detail the UV shot has in comparison to the white light image. Quite easy to understand actually, since the (theoretical) resolution of that lens used rises by a factor of 546nm/365nm = ca 1.5x (if we use the median for white light).

So since I had a feeling someone might ask how a bee might see that situation, here my sythesized bee vision version for your viewing pleasure:




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