Sunday, October 21, 2018

[UV, VIS, IR] Lyman Alpha deep UV lenses II

Oh well, it has been five years, but now I finally infinity-converted these very special lenses...

Back back a little in time: When I was able to acquire three prototypes of those lenses, made 1992, in 2012, which came from the estate of the inventor, Richard Nye and his company, Nye Optical of La Mesa CA, I was very excited to find such lenses able to record in deep UV. But they turned out to be a bit tricky to convert and adapt to digital cameras. Now with mirrorless ones, it looked rather promising...

So, these scientific lenses Mr Nye invented and custom made, were for deep UV recording (capable to even work beyond 200nm, especially made to record the 121nm Lyman alpha lines, hence the name). It is a catoptric (reflex) Cassegrain design, which came in f2.8/200mm and f1.1/90mm (and some other) versions for full format cameras, but also for intensifier tubes and video cameras (25mm image circle, like the f1.1/90mm), with focusing from 250mm to infinity and some adjustable 50mm resp.18mm back focal length. And now I have them working on my Panasonic GH4 camera....

[click on image to see a larger one]



Inside the aluminum housing resides an about 25mm (1") thick quartz (ZERODUR most likely) mirror block, front aluminized plus a secondary mirror (most likely made of the same material) held by an adjustable metal "spider" in front of that first one. Quite built like a small 90mm diameter Cassegrain astronomical telescope.

DOF at one (1) meter (3ft) is as thin as a razor blade when using the Lyman Alpha f1.1/90mm lens and that doughnut shaped bokeh etc. makes it fun to use.

Here now a few images in visible light, UV will follow shortly...





The very thin DOF of course generates those doughnut shaped bokeh bubbles, but by chosing a proper i.e. less noisy background it can be "tamed".

I have written about those lenses 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

Friday, October 12, 2018

Common Sunflower - Helianthus annuus in reflected ultraviolet photography and simulated bee vision

Today shots of a flower everybody has already seen, a common Sunflower - Helianthus annuus in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter as well as in simulated bee vision using my XBV filter. Lens was my UV-Nikkor 105mm quartz flourite lens. Light source was sunlight. All shots were done at f8.

[click on image to see a larger one]

Human vision:
 

Reflected UV:
 

Simulated bee vision:
 

Triptych of human vision, UV, simulated butterfly and bee vision (left to right):
 

This flower has a specific and unique UV pattern, its petal tops are brightly UV reflective around 365nm and the rest and its center is UV dark forming an UV bullseye pattern, and all this gets nicely visible, also in simulated bee vision.

I have written about sunflowers 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

Tuesday, September 11, 2018

Black-Eyed-Susan - Rudbeckia fulgida: HDTV video in human vision and simulated bee vision

Today video shots of a famous "UV-flower" Black-Eyed-Susan - Rudbeckia fulgida in human and simulated bee vision. All shots were done at f5.6 in visual  videography and using my XBV filter for simulated bee vision. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight.

[click on image to see a larger one]

Human vision (VIS):
 

Simulated bee vision (BV):
 

And now VIS and BV HDTV videos shot in parallel of a selected flower with pollinating bees:
Black-Eyed-Susans have a distinct UV reflection "bulls eye" pattern, its petals have a quite UV dark center (visible as green in simulated bee vision) and the outside part is quite UV bright around 365nm (visible as bright yellow in sim. bee vision). All this gets nicely visible, also in simulated bee vision as well as in the HDTV videos.

I have written about that flower 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

Thursday, August 23, 2018

UV-Nikkor 105mm vs Coastal Optical systems 105mm lens for reflected ultraviolet (UV) photography II

I got another Coastal Optics (now JENOPTIK CoastalOpt®) f4.5 / 105mm lens, so today about shooting with two dedicated UV lenses, the Coastal Optical Systems / Jenoptik UV-Micro-Apo f4.5 / 105mm and the classic UV lens, the UV-Nikkor f4.5 / 105mm in a truely non-scientific photographic comparision at shooting in reflected UV, using the Baader-U filter at sunlight. Both lenses were used fully open at f4.5.

[click on image to see a larger one]

Chimney about 10m away:


Detail:


Chimney about 20m away:



Detail:


Roof:


Detail:


Close-up:


Detail:


The UV-Nikkor 105mm image is shown on the left side, the Coastal Optical Systems 105mm on the right side. White balance was done for the UV-Nikkor 105mm.

The UV-Nikkor 105mm seems to have (quite) an edge over the Coastal Optics 105mm in terms of sharpness and contrast, when used fully open at f4.5. That difference will get smaller stopped down, and the Coastal will gain sharpness and also contrast, as my previous test has shown.

Both lenses require about the same white balance, due to their flat UV transmission and show about identical exposure, with exposure times having a slight nod towards the Coastal Optics lens (1/3 stop less), which in practice is rather insignificant. See the following transmission spectra I have measured, which shows that the modern broad range UV-VIS BBAR coating the Coastal Optics lens has offers some higher transmission on average which actually calculates as 1/3 stop difference:




PS: But there is a rather unexpected feature the Coastal Optics lens has (identical with both lenses I have): Its Coastal made Nikon-F mount is 0.3mm wider than the original Nikon-F mount which leads to a rather wobbly fit. To cure that, I bent the camera adapter springs a bit wider to achieve the needed tight fit.



I have written about that Coastal Optics 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

Friday, August 17, 2018

Exhibit at Museum Mensch und Natur, Nymphenburg Palace, Munich, Bavaria Germany II

Today more about that German Museum, Mensch und Natur (Museum of Man and Nature) located at the famous Nymphenburg Palace in Munich, Bavaria, Germany which I support with my images for a now open exhibit about insects named "Knallbunt und unsichtbar" ("extremely colorful and invisible") which will be shown July 6 - November 4, 2018. It includes works of mine about (simulated) butterfly and bee vision.

[click on image to see a larger one]

Here now a few shots I got from the Museum about this exhibit:


all images (C) Museum Mensch und Natur

The exhibits shows the difference of our human vision and the vision of butterflies and bees (simulated) using special viewers under each image.

I'm wishing the museum and its visitors a successful exhibit, certainly worth going to with family and friends!

I have written about that previously 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, August 5, 2018

Black-Eyed-Susan - Rudbeckia fulgida in reflected ultraviolet photography and simulated bee and butterfly vision IV

Today more shots of a famous "UV-flower" Black-Eyed-Susan - Rudbeckia fulgida in reflected ultraviolet photography and simulated bee and butterfly vision. All shots were done at f5.6 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, as well as my XBV filters for simulated bee and butterfly vision. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight.

[click on image to see a larger one]

Human vision:
 

Reflected UV:
 

Simulated butterfly vision:
 

Simulated bee vision:
 

Quadriptych of human vision, UV, simulated butterfly and bee vision (left to right, top to bottom):
 

Black-Eyed-Susans have a distinct UV reflection "bulls eye" pattern, its petals have a quite UV dark center and the outside part is quite UV bright around 365nm and all this gets nicely visible, also in simulated bee and butterfly vision.

I have written about that flower 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

Dahlia using Negative Space in reflected ultraviolet photography and simulated butterfly and bee vision

Today shots of a decorative flower of the Asteraceae family, Dahlia sp in reflected ultraviolet photography and simulated bee and butterfly vision. All shots were done at f5.6 in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, as well as my XBV filters for simulated bee and butterfly vision. Lens was a UV-Nikkor 105mm quartz fluorite lens. Light source was sunlight.

[click on image to see a larger one]

Human vision:
 

Reflected UV:
 

Simulated butterfly vision:
 

Simulated bee vision:
 

Quadriptych of human vision, UV, simulated butterfly and bee vision (left to right, top to bottom):
 

This pretty flower has no specific UV pattern, its flower petals are UV dark, whereas the flower center is UV reflective, but this actually creates a negative space where the UV reflective center stands out against by massively increasing contrast - and all this gets nicely visible, also in simulated bee and butterfly vision.

I have written about that negative space concept HERE, California poppy and Bermuda buttercup uses that too! 
 
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