Zinnia angustifolia mix: human vision vs simulated bee vison; reflected UV ultraviolet photography

From a walk through the beautiful Hermannshof, Weinheim, Germany I brought home these shots of a mix of flowering Zinnia angustifolia, that special mexican variety. I took some shots in normal human vision VIS, in UV using the Baader-U filter, as well as in simulated bee vision using my XBV2 and new XBV6 filters respectively. So here comes Z. angustifolia in its multispectral representation.

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Visual shot:


Simulated bee vison using XBV2 filter:


Simulated bee vison using XBV6 filter:


UV using Baader-U filter:


VIS-BV-UV quadriptych:


These Zinnia specimens expose their well known deep into reaching UV (<360nm) tip pattern very nicely, on some there even is no visible pattern at all.

As you may have noticed, I'm still working on my bee vision (BV) filters; BV6 is one with very intensive colors and much shorter exposure time, due to new filter glass combinations.

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

Petri Kuribayashi 35mm vs CERCO quartz fluorite lens for reflected UV photography III

Here now a test using that previously mentioned Petri Kuribayashi f3.5/35mm lens when used with the standard UV transmission filter, the Baader-U as well as my shorter wave Jupiter-U filter, compared to the Noflexar f3.5/35mm lens, but now also in comparison to a quartz fluorite lens, here the CERCO f4.1/94mm.

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The CERCO 94mm delivers a peak transmission of about 55% at 350nm when used with the Baader-U filter and about 48% at 338nm when using the Jupiter-U filter. That compared to the Kuri 35mm which has a peak transmission of about 58% at 362nm, wheras the Noflexar 35mm shows one of about 45% at 365nm when teh Baader-U filter is used. And when using the Jupiter-U filter, the Kuri 35mm has a peak transmission of about 43% at 350nm, wheras the Noflexar 35mm shows one of about 30% at 358nm.

So using the very same filters, the CERCO 94mm reaches much deeper into UV, which could have been expected, based on its flat UV transmission. However it is a much more expensive lens and quite hard to find, so the Kuri 35mm certainly is a welcome new find for the aspiring UV shooter, also considering that it virtually has no focus shift between UV and visible light.


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

Petri Kuribayashi f3.5/35mm lens for reflected UV photography II

Here now a test using that previously mentioned Petri Kuribayashi f3.5/35mm lens when used with the standard UV transmission filter, the Baader-U as well as my shorter wave Jupiter-U filter, compared to the Noflexar f3.5/35mm lens.

[click on image to see a larger one]



When using the Baader-U filter, the Kuri 35mm has a peak transmission of about 58% at 362nm, wheras the Noflexar 35mm shows one of about 45% at 365nm, that is a gain of about 0.4 stops for the Kuri 35mm.

When using the Jupiter-U filter, the Kuri 35mm has a peak transmission of about 43% at 350nm, wheras the Noflexar 35mm shows one of about 30% at 358nm, that is a gain of about 0.5 stops for the Kuri 35mm, based on its deeper reach into UV.

There is a part III about this lens HERE.

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

Flower decay made visible using reflected UV ultraviolet photography II

While I was shooting flowers at Hermahnshof, Weinheim park, I noticed that in UV the wilting / ageing / decay of a flower can be easily detected, wheras in visible light this is not visible to us humans. I have written about that effect earlier here.

A UV sensitive camera, Cerco 94mm lens, Baader-U resp. UV/IR Cut filter was used; standardized UV palette using my ReflectionDisc

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VIS (left) - UV (right):


The larger, yellow Helianthus tuberosus flower on the right side clearly shows that it has aged and will be wilting soon. In reflcted UV things get much easier to see immediately. So I'm sure pollinators (bees) knew that way before us...


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

Petri Kuribayashi f3.5/35mm lens for reflected UV photography

Now this today was based on an information I got from a forum,  that the Petri Kuribayashi f3.5/35mm lens was very capable of working for reflected UV photography.

I tested that lens and it performed even better (pink line) than the well known Noflexar f3.5/35mm lens (red line), reaching down into UV to about 320nm. At 365nm it even has a 12% higher transmission (1/4 stop).

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There are a few similar looking re-branded emanations of that Kuri lens, but with lesser performance, so be aware of that. These and a few other emanations of basically the same lens were not my finds, but Boon Tang and Alex Holovachov deserve the credit for those finds and bringing it to my attention. I'm not sure if later made models may have the same good transmittance, as the coating may have been changed to more modern ones that unfortunately suppress UV to pass (blue coating color is an indication for that). Here for instance the Prinzgalaxy f3.5/35mm in comparison, that shows a about 20% lower transmission at 365nm, but still useful (1/2 stop less):



And here one of SOLIGOR brand:


Here now a quick photographic test of that original Kuribayashi 35mm lens, which shows virtually no focus shift (1.03%), as well as very good sharpness and very good contrast in reflected UV using the Baader-U filter:



Here the visual shot for comparison:


The little downside that it only focuses to about one meter (3 ft) can be overcome by using a small helicoid or tube, if so needed. Here the Noflexar 35mm has an edge, as it has a built in close focus ability to about 1:2 (0.5x) magnification.

So this "zebra" barrel styled Kuribayashi lens from the 50ies / 60ies is a very welcomed new lens to the very few "normal" i.e. non quartz fluorite ones that does perform very well.

There is a part II about this lens HERE.

Photographic comparison between the Kuribayashi and the Soligor lens is HERE.


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