Monday, December 31, 2018

Oncostele Wildcat 'Golden Red Star' in visible, reflected UV, simulated bee and butterfly vision - differentials

Today shots of an Orchid hybride, Oncostele Wildcat 'Golden Red Star' in reflected ultraviolet photography as well as simulated bee and butterfly vision  - but also in differential ("psychedelic") presentation. UV filter used was the Baader-U filter, my "work horse" filter for reflected UV as well as my proprietary XBV filters. All shots were done at f8 using an UV-Nikkor f4.5/105mm lens. Light source used was a modified for high UV output Xenon flash.

[click on image to see a larger one]

Human Vision (VIS):
 

Reflected UV (Baader-U):
 

Simulated Butterfly Vision:
 

Simulated Bee Vision:
 

Human Vision (VIS) - Ultraviolet (UV) Differential:
 

Simulated Butterfly Vision (BU) - Ultraviolet (UV) Differential:
 

Simulated Bee Vision (Bee) - Ultraviolet (UV) Differential:
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible, also in Differential form (UV reflection shows as light blue)

I have written more about this orchid HERE and about Differentials 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

Saturday, December 29, 2018

Oncostele orchid in visible, reflected UV, UV-Nikkor vs Quartz Fluoride lens - psychedelic

I have done shots of an Orchid hybride, Oncostele Wildcat 'Golden Red Star' in reflected ultraviolet photography using an UV-Nikkor f4.5 / 105mm lens in comparison to an older f3.2 / 81mm Quartz Fluoride Condensor lens from an older UV-VIS spectrometer system before here. UV filter used was the Baader-U filter, my "work horse" filter for reflected UV. All shots were done at approx. f8. Light source used was a modified for high UV output Xenon flash.

Now today I'd like to show differential of those VIS and UV images, making strinkingly visible the difference, hence why I call those images "psychedelic"....

[click on image to see a larger one]

UV-Nikkor 105mm Lens: 

Human Vision (VIS):
 

Reflected UV (Baader-U):
 

Psychedelic (Differential VIS-UV):
 


Quartz Fluoride Condensor Lens 81mm: 

Human Vision (VIS):
 

Reflected UV (Baader-U):
 


Psychedelic (Differential VIS-UV):
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible, also in this psychedelic differential presentation, on both used lenses.

I have written more about this orchid HERE  and more about that old quartz fluoride condensor lens HERE.

More such psychedelic differential images may be see 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

Thursday, December 27, 2018

Oncostele orchid in visible, reflected UV, simulated bee and butterfly vision UV-Nikkor vs Quartz Fluoride lens

Today shots of an Orchid hybride, Oncostele Wildcat 'Golden Red Star' in reflected ultraviolet photography as well as simulated bee and butterfly vision using an UV-Nikkor f4.5 / 105mm lens in comparison to an older f3.2 / 81mm Quartz Fluoride Condensor lens from an older UV-VIS spectrometer system. A variable aperture was added to the Quartz Fluoride Condensor lens to allow stopping down. UV filter used was the Baader-U filter, my "work horse" filter for reflected UV as well as my proprietary XBV filters for simulated bee and butterfly vision. All shots were done at approx. f8. Light source used was a modified for high UV output Xenon flash.

[click on image to see a larger one]

UV-Nikkor 105mm Lens: 

Human Vision (VIS):
 

Reflected UV (Baader-U):
 

Simulated Butterfly Vision:
 

Simulated Bee Vision:
 

Quadriptych of VIS, UV, sim. Butterfly and Bee vision (left to right, top to bottom):
 


Quartz Fluoride Condensor Lens 81mm: 

Human Vision (VIS):
 

Reflected UV (Baader-U):
 


Simulated Butterfly Vision:
 

Simulated Bee Vision:
 

Quadriptych of VIS, UV, sim. Butterfly and Bee vision (left to right, top to bottom):
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible, also in simulated Bee and Butterfly vision, on both used lenses.

The lenses itself differ in focal length, 105mm for the UV-Nikkor vs 81mm for the Quartz Fluoride Condensor lens, and lens speed f4.5 vs f3.2 but other than that they are quite comparable: there is hardly any focus shift, just sharpness and contrast is higher with the rather expensive UV-Nikkor lens compared to the Quartz Fluoride Condensor lens, quite as expected. Other than that this old lens does very well, but it only covers mft sensor format, possibly APS-C (with another modification).

I have written more about this orchid HERE  and more about that old quartz fluoride condensor 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

Thursday, December 20, 2018

NOVOFLEX T-NOFLEXAR 400mm for reflected ultraviolet (UV) photography


So today it is about a lens I had laying around for many years, intended to use for reflected ultraviolet photography, as it is a simple achromat from what I know, the NOVOFLEX T-NOFLEXAR 5.6/400mm.

To find out if there is a chance to get it to work, best aside from just trying out, to chech with a suitable spectrometer if there is some useful UV transmission - and this will be shown here. As a comparison, I will use two other lenses, both well known to work in UV, the Kuribayashi 3.4/35mm and the NOFLEXAR 3.5/35mm lens (also made by NOVOFLEX).

[click on image to see a larger one]


Now this transmission spectra clear shows, that althought the T-Noflexar 400mm cannot beat the Kuribayashi 35mm lens, it is very close to the Noflexar 35mm lens transmission, which is considered quite useful for reflected UV photography. It delivers about 67% transmission at 365nm, the Kuribayashi does 78% there.

Remark: the 100% line reflects the transmission of a white SPECTRALON (R) reflection standard with 99% reflection in the 300-700nm region, so this result should be a true representation of the lens transmission.

I will shoot a few test images in visible light and UV, weather permitting. It is dull grey winter weather now, so that might be in coming spring...


I have written about lenses for UV before 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

Sunday, December 16, 2018

Oncostele Wildcat 'Golden Red Star' in visible, reflected UV, simulated bee and butterfly vision

Today shots of an Orchid hybride, Oncostele Wildcat 'Golden Red Star' in reflected ultraviolet photography as well as simulated bee and butterfly vision using an UV-Nikkor f4.5/105mm lens. UV filter used was the Baader-U filter, my "work horse" filter for reflected UV as well as my proprietary XBV filters. All shots were done at f8. Light source used was a modified for high UV output Xenon flash.

[click on image to see a larger one]

Human Vision (VIS):
 

Reflected UV (Baader-U):
 

Reflected UV image at 340nm peak (IDAS UV372):
 

Simulated Butterfly Vision:
 

Simulated Bee Vision:
 

Quadriptych of VIS, UV, sim. Butterfly and Bee vision (left to right, top to bottom):
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible, also in simulated Bee and Butterfly vision.

I have written more about this orchid 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

Tuesday, December 11, 2018

Baader-U Venus filter versus OPTOLONG Venus-U filter

Today about a new (to me) UV transmitting filter for reflected ultraviolet (UV) photography: the 2" OPTOLONG VENUS-U filter. This filter I have compared here with my work-horse UV filter, the 2" Baader-U Venus filter.

First it is about the resulting images and of course if there might be any IR leakage. The latter is quite important, as in early morning or late evening sunlight, where IR is predominant or when shooting against the sun or when reflective elements are present in an image,  IR leakage may lead to loss of contrast, or even obscuring the wanted UV details.

Now on to my tests which have been done using as a target an Oncostele orchid which has quite some prominent UV marks. Lens used was an UV-Nikkor 105mm, camera a modified Panasonic GH4, light a modified for high UV output Xenon studio flash. All shots were one at f8.

[click on image to see a larger one]

Baader-U filter (left) vs Optolong Venus filter (right:

Baader-U filter (left) vs Optolong Venus filter (right) - whitebalanced against gray BG:


It gets quite obvious that there is something going on here in terms of leakage, as the image shot with the Optolong Venus filter shows some blueish hint visible all over the orchid and also there is some central flare visible, wheras the Baader-U Venusfilter delivers a tack sharp and high contrast image. After whitebalacing against the gray background, which obviously was not possible with the Optolong filter, the result gets even worse, a rather muddy looking image results from the Optolong filter. In terms of exposure, the Baader U filter also has a slight 0.3 stop advantage over the Optolong filter.

Once I will have done some spectrometric transmission measuerements, I will certainly post those here later.

So please draw your own conclusions from this, if you would consider this a valuable filter for reflected UV photography. I will certainly continue to use my "work-horse" UV filter, the Baader-U.

I have written about IR leakage in filters for reflected UV photography 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

University of Zurich Zoological Museum exhibit «Insects - essential to life!»

The Zoological Museum of the University of Zurich, Switzerland has just opened the doors of a new special exhibit "Insects - essential to life!". It will be on display December 11, 2018 - June 30, 2019.

Included in this is a video with some of my best multispectral works, which my partner for this, animation artist Robin Noorda, has converted into a video presentation, named "Insecta Spectra".

Some insects (butterflies, Bees, ...) and also some animals (birds, fish, degus,..) are able to see ultraviolet (UV) light. Bees for instance can see Green and Blue and UV, but no RED, but butterflies and birds can see Red, Green and Blue and UV, so both can see what we humans cannot see - UV. To make that visible for us humans, I developed a special filtering and optical mapping method, which allows to simulate, how we would see the world, if we had such special UV receptive eyes.

Have a look at the preview video clip [click]:

Certainly and exhibit worth visiting with the whole family!

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

Monday, December 3, 2018

Oncostele Wildcat 'Golden Red Star' in visible and reflected ultraviolet (UV) light

Today shots of an Orchid hybride, Oncostele Wildcat 'Golden Red Star' in reflected ultraviolet photography with a UV-Nikkor f4.5/105mm lens. UV filter used was the Baader-U filter, my "work horse" filter for reflected UV. All shots were done at f8 for the UV-Nikkor. Light source used was a modified for high UV output Xenon flash.

[click on image to see a larger one]

Visual vs reflected UV (Baader-U):
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible.

I have written more about this orchid 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

Saturday, December 1, 2018

[UV, VIS, IR] Lyman Alpha deep UV lenses V - Oncostele orchid

Today shots of a Orchid hybride (Oncostele Wildcat 'Golden Red Star') in reflected ultraviolet photography with a NYE OPTICAL Lyman-Alpha I f2.8/100mm UV-VIS-NIR lens. UV filters used was the Baader-U filter for the Lyman Alpha 100mm, rear mounted. All shots were done at f2.8 as the Lyman Alpha lens has no iris. Light source used was two different Nichia 365nm UV-LEDs, one a cheap Convoy S2 UV mini torch.

[click on image to see a larger one]

For reference, visible light shot (UV-Nikkor 105mm):
 

Lyman Alpha I lens UV using Baader-U filter and Convoy S2 UV LED:
 

Lyman Alpha I lens UV using Baader-U filter and Convoy S2 UV LED:
 

Lyman Alpha I lens UV using Baader-U filter and strong Nichia UV LED:
 

This orchid has a very specific UV pattern, its petals are very UV dark, but its lower petal lip has on the lower center a very UV bright spot as well as on its center "nose" formation an UV reflecting spot and all this gets nicely visible, also with this Lyman Alpha I f2.8/200mm mirror only lens.

I have written about the Nye Lyman-Alpha lenses previously HERE and about this Orchid 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