Showing posts with label catadioptric. Show all posts
Showing posts with label catadioptric. Show all posts

Saturday, November 6, 2021

Russian Catadioptric ZIKAR-1A f1.2/100mm anastigmat lens for space use

Today about a lens I have forgotten to write about it here: the Russian catadioptric ZIKAR-1A f1.2/100mm anastigmat lens I found in 2018, which had been developed for the Russian space defence program, to detect fired rockets aiming at the (then) USSR from about 45.000 km away, mounted at some special (unknown) camera system from a satellite in orbit around earth. It is a catadioptric system with two Beryllium mirrors, very fast f1.2/100mm and some fluorite auxiliary lenses. Several such systems were successfully launched into space and were in operation several years long.

(source: net)

I found a russian document about it HERE (Google translated) :
On September 19, 1972, the first space-520 experimental SPACECRAFT was launched from the Plesetsk cosmodrome. On Board in addition to the control equipment and reset information were installed two types of BAO: television (MBT-A) and heat direction finding (105-A). The TV-type equipment was a two-chamber receiver with IR-vidicons Radian with a lens”Zikar-1A". One camera had a relatively wide angle of view (SPK) and the other narrow band (UPK). The field of vision of the CPC was inside the field of vision of the SPC. The TP-type equipment had one line of fifty sensitive elements scanning the field with the help of a swinging mirror. The total field of view was no more than 10 square degrees. (end)


From that and more data I found that it was designed for SWIR, 1.5 - 2.5 microns, I assumed that this lens would only useful for IR and possible visible light, but having it on my spectrometric UV-VIS-IR system surprisingly revealed that it could be used in UV down to 320nm!

(own spectrometric measurement)


Further research showed that his lens was a part of TB (телевизионная аппаратура) unit, possibly used as an auxiliary lens to help aiming a much larger main lens unit. That main TП (теплопеленгатор) unit was a massive lens with a main mirror having a diameter of one meter (100 centimeters or 1.000 millimeters) [early versions УС-К had a diameter of 50cm; later versions УС-КМО had 100cm (1.000 millimeters)].

That impressive main unit УС-К/УС-КМО looked like this:

(source: net)

1 - a mirror made of vitrified beryllium with a diameter of 60 cm, the surface shape being a convex hyperbola of the second order.
2 - a mirror made of vitrified beryllium with a diameter of 100 cm, a surface shape being an aspheric of the 12th order.
3 - correcting lenses made of fluorides of calcium and lithium.


That ZIKAR-1A 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. That will not be easy, as it has a very short back focal length.

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


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

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...
 

Monday, February 12, 2018

ZUFAR 4/350mm quartz fluorite catadioptric lens II

Today more about that Quartz Fluorite catadioptric ZUFAR-2CA f4/350mm anastigmat lens which took me over 10 years to find. It had been developed for the Soviet MARS 2 to 5 missions to planet Mars, was made of synthetic Quartz and Calcium Fluorite (CaF2) crystals to be able to work in UV and also visible light, thus allowing to take images 300-700nm without focus shift.


So today a few first test shots using this very special lens, due to lack of the mount which need to be designed and made, just some freelensing shots. "Freelensing" means holding the lens in front of the camera without any mount in between the two (!).

Here some visible light shots, showing how this lens performs. This first one is about 150 meters away:




and the following one about 15 meters:



The lack of chromatic aberration gets easily visible on that golden ball as well as on these shiny stainless steel exhaust pipes.

Now on to reflected UV images (300-400nm), here right out of camera:



and here with whitebalancing applied:


Being able to handheld a f4 350mm lens and shooting in reflected UV (300-400nm) is rather astonishing, a proof how much UV this lens is able to transmit. More about this lens will certainly follow here...

I have written about this lens before HERE


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

Monday, February 5, 2018

ZUFAR 4/350mm quartz fluorite catadioptric lens

Today about a Quartz Fluorite catadioptric ZUFAR-2CA f4/350mm anastigmat lens which took me over 10 years to locate. It had been developed for the Soviet MARS 2 to 5 missions to planet Mars.



It was made of synthetic Quartz and Calcium Fluorite (CaF2) crystals to be able to work in UV and also visible light, 300-700nm without focus shift, so actually is an apochromatic (APO) f4/350mm catadioptric lens. The whole useful wavelength range is 230-700nm. Lens transmission is 60-65% and the lens resolution is 57 lpm in its center, 47 lpm in corners. Viewing angle is approx. 6 degrees. There has also been made a ZUFAR-1 lens with f4 / 500mm and 4 degrees viewing angle.

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)

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


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.

There is more about this lens HERE including some first images taken with it.


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