Saturday, November 17, 2018

ZUFAR 4/350mm and its prototype quartz fluorite catadioptric lens III

Today again about that Quartz Fluorite catadioptric ZUFAR-2CA f4/350mm anastigmat lens which had been developed for the Soviet MARS 2 to 5 missions to planet Mars. I'm rather excited to report that I  found and bought the grandfather of this ZUFAR-2 space lens from planet Mars exploration, a prototype lens with a very different internal name Ob-512, but company data (LOMO) I was able to locate confirmed my suspicion, it is indeed one or even "the" factory prototype of it.


Top Ob-512 prototype, Bottom: ZUFAR-2CAM lens

The prototype OB-512 also was made of synthetic Quartz and Calcium Fluorite (CaF2) crystals to be able to work in UV and also visible light, designed for 200-700nm without focus shift, so actually is an apochromatic (APO) f4.7/350mm catadioptric lens as per its lens passport. Lens transmission is >57%. Viewing angle is approx. 3 degrees (later 4 degrees). Image diameter 24.6mm. 51mm back focal length. Its weight is 2.2 kilograms, which was later changed in the final ZUFAR-2 CA lens to 1.8 kg using special alloys, as every gram counted then for space missions.

Those ZUFAR lenses have been designed in the 70s under the lead of Institute head and chief designer Prof. Volosov together with N. Khmelnikova, I. Driatskaya, K. Mikhailova at GOI, the russian state lens design institute in St. Petersburg / Leningrad. Details were published by Prof Volosov in 1974.

(Made for my use by my dear friend Marco Cavina)


Optical data of the Ob-512 prototxpe as per Volossov et al.

This lens was made to be used on a very elaborate camera system which could take multispectral images on film, develop that and scan it and send the scanned data back to Earth in selectable resolutions (up to 2000x2000 pix, which took over one hour to transmit).


NASA also wrote about this lens (quote):

Zufar objectives were used on the television cameras carried by the Mars-2, 3, 4, and 5 spacecraft. The compact catadioptric quartz-fluorite anastigmat was developed as a result of research on the possible optical arrangements of lens and mirror-lens systems meeting the rigid criteria for spaceborne operation. The system is characterized by precise correction of all aberrations over a broad spectral range, about 300-700 nm. The spectral transmission is about 60% over this range. The Zufar-2CA version of the objective has a geometric aperture ratio of 1:4 and a focal length of 350 mm. The image format is 24 x 24 mm. The housing is 164 mm long and 130 mm in diameter, and the mass of the objective is 1500 g.

Here one of the published images from Mars taken on Mars-5 mission:



The lens will be given a suitable adaption to fit my digital multispectral cameras and I will certainly take multispectral photos with it as soon as possible and report about here later on.

Data of this lens, as well as its normal (= non catadioptric) quartz fluorite sister lenses with shorter focal length may be found on my macrolenses database site HERE

There is more about this lens HERE.


Stay tuned, more will follow on that fascinating subject...
 

Tuesday, October 23, 2018

LDM-1 long distance microscope for reflected UV (ultraviolet) light and African Violet

Today shots of an African Violet flower in reflected ultraviolet photography using a UV filter stack consisting of SCHOTT UG1 + BG40. All shots were done at f11. Lens was a rather rare LDM-1(s) 800mm mirror only lens, the close-up using the AP300 achromatic cloe-up lens, which was once sold with this lens system. Light source used was a 365nm Nichia UV LED light.

[click on image to see a larger one]

LDM-1(s) alone:
 

LDM-1(s) with the AP300 achromatic close-up lens:
 

And now here some comparison images I have shot with my "work horse" UV-Nikkor 105mm plus Baader-U filter.

Overview:
 

Closeup at closest focusing distance:
 

I have written about this LDM-1 lens 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

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