The “Unitron History Research Project” was initiated in September 2014 as a result of community discussion on the Cloudy Nights Forum.  Its success is due in great part to the efforts of the dedicated classic telescope community, and individual contributions, participation, and continued support.

As you recall, my initial hope was that individuals with information on Unitron and Nihon Seiko, and owners of the larger aperture Polarex and Unitron’s would take advantage of this site to pass on that information.  Its success was once again proven based on the photos and information that Alex Boot passed along on both the Polarex-Unitron Model 900 and about Nihon Seiko.  Additional details on the discovery, recovery, and restoration of that telescope are being covered under a separate Features Page, Polarex-Unitron Model 900.

Polarex-Unitron Model 900

Overall, the classic telescope community has benefited from the information provided by Unitron and Polarex enthusiasts worldwide including: Australia, Belgium, Canada, Denmark, Greece, Italy, Japan, Netherlands, Norway, as well as from all over the United States.   I expect this trend will continue as we expand our knowledge of these great telescope brands and as I complete the writing of the history in the three sections under the History Page: “The Glory Days”, “The Transition”, and “The Demise”.

NEAF 2018 – Model 510 and Model 128

NEAF 2018 – Unitron “Row”

During this period I’ve also had the pleasure of meeting some great individuals who are also enthusiastic collectors of these fine telescopes, and had the opportunity to visit and/or observe through 6 inch Unitron telescopes in five locations including Texas, Arizona, Connecticut, Vermont and Michigan.  For me these experiences have been the thrills of a lifetime!

The star party at Rafes Urban Astronomy Center held in March 2015 was especially gratifying…as was the opportunity to work with the members of the Green Mountain Association of Amateur Astronomers – dedicated individuals responsible for taking care of the 6 inch Unitron at Castleton University in Vermont.


Ferris State University, Michigan – 2016


Rafes, Denton, Texas – 2015


Rafes, Denton, Texas – 2015


Castleton University, Vermont – 2015

“The Project: Purpose and Motivation”

As an original owner of two Unitron telescopes, I  have been an admirer of these fine instruments since first reading about them in Sky and Telescope magazine back in the 1950’s.  With that as part of my motivation, I decided to take on as a retirement project the research and documentation of the history of the Unitron Company. I recognize there are some very good articles that document the history already hosted on various sites.  However, it is my belief there is good justification to consolidate this information in an effort to provide a more comprehensive and detailed history.  It is also my belief there are good sources still available that can provide personal insight into the company, but time is running out to take advantage of these sources.  This website is intended to serve as a means for those sources to provide that information not only on the history, but hopefully on some of the hidden large aperture Unitron and Polarex telescopes.

The two primary objectives I proposed for this project are to:

1.  Develop a comprehensive and verifiable history of the Unitron USA Company from the early 1950s until the early 1990s, and include what history can be uncovered about its supplier, Nihon Seiko

2.  Document the existing 5 inch and larger telescopes; there are no accurate records of production numbers

Dave Komar, Culpeper, VA

“Look deep into nature, and then you will understand everything better.” Albert Einstein

Updated February 2018


  1. What a wonderful resource for these amazing telescopes. We Unitron aficionados are indebted. Thank you.

  2. Dear friends, I’m in México City, I have collected for years Polarex-Unitron Telescopes and accesories and I’ve got almost all models except the five and six inches, as many of you I have always sought the six inches and this website is fantastic it allows us to enjoy these beautiful old instruments. In my search for the six inches here in México I got in a University a beautiful old six inches Goto Telescope with all accesories, pedestal and astocamara original.

    Thanks for this website.
    Kind Regars.

    • Carlos de la Torre

      Dear Friend:
      I am also in México City and “was” very enthusiastic about Astronomy and Telescopes.
      To my knowledge, The only six inch Polarex Unitron in Mexico City was or maybe still is the property of the AAM Asociacion Astronomical de Mexico, or SAM Sociedad Astronomical de Mexico. They used to have this beautiful instrument in an observatory at a park, I think, Jardin Balbuena or another park close about a block from Calzada de Tlalpan. Start your search by SAM. Maybe the place is stillthere…
      Carlos de la Torre

      • yes we still have it. it is its own cupula and was in was in good shape, at least two years ago when I used it..
        we stay in the SAMs building in the Parque Xicotencatl in the Alamos Colonia not far away fron Calzada de Tlalpan nearest Metro Station Viaducto. short walk to park. 6 blocks away..
        we meet there mondays at 8:00 pm mostly.
        This time the year it is very difficult to have clear nights. By october weather can be much better
        send me a mail matabuenap@gmail.com
        we have good meetings for rainy nights and lectures
        Keep in touch if it interest you
        Hasta la vista

      • Javeline Philippe

        Few Years ago while in Mexico City I met with someone by the name of Carlos de la Torre.I would like to know if he the real person that I got the chance to talk to. He said to me that he studied Astronomy, it seems to me that Astronomy is a beautiful science as I read your intervention about. Can you reach me by my email posted below or you can call me at 3474470689 for more details.

    • Ernesto
      No te puedo localizar por celular
      We need to talk
      Call me
      Pedro Matabuena

  3. Thank you for this great website. I sent some information to you via the unitronhistory2014@gmail.com address concerning the picture I found in a 1969 publication of a 6.0″ Unitron on the roof of Villanova University in Pennsylvania. Its current location/condition is unknown but I might just do some digging and find out.
    thanks again.

  4. I just read the Steve Franks Interview; Very interesting ! — it fits nicely with my own impression of the role of Unitron as a primarily importing, marketing, repacking / selling and distributing agency.

    Looking forward to your posting of the other announced interviews, and hopfully to your next step of researching the role of Nihon Seiko in the design and production of these telescopes in Japan (I realize that won’t be easy though).

    Thanks for your effort.

  5. As refractor and Unitron fan, i appreciate a lot your nice project. Well done & congratulation!

  6. Wonderful site with much information about the history of Unitron/Polarex/Weltblick/Mercurius.
    I’ve got almost all models 40mm -102mm and still have a 75mm alt-az which performs fantastic.
    Keep up the good work!

  7. Thanks for this resourceful site. Wish you luck on locating those precious 6″ gems. It is a honor to have my Polarex NS-131 displayed in your gallery.

    Stefan Thiele/Germany

  8. I own a Polarex D=75 / F=1200 complete with a 220V motor. I have owned it since the early 1990s. I’m from Sweden and my scope is renamed to “Meridian”. It’s marked on the motor drive “Meridian 220V model 131 NS” Even the focuser is marked “NS” and “Meridian” in the same style as the Unitron or Polarex scopes. I think “NS” stand for Nihon Seiko. Even my eyepieces are marked “NS” (like “9mm SYM” and “NS”, instead of Unitron or Polarex)

    Now I know that the “Meridian” was a small firm, owned by a man called Björn Hedvall. Björn Hedvall (no longer alive) was supervisor for the public observatory in my town Gothenburg. The observatory (a tiny shelter from 1929, placed in the city park) was equipped with one 6 inch tube together with a 4 inch guide scope. All his refractor scopes were from Unitron/Polarex (Nihon Seiko), but marked “Meridian”.

    My scope was equipped with one 65mm/900f scope and a viewfinder 8X 30mm. But I sold the guide scope (I didn’t know how rare this scope was). I regret that big time now!
    (sorry for my poor English)

  9. I have my fathers Unitron 3 inch, I think model 140. Does anyone know where I can find a Unitron SLR camera adapter? My father had one, but loaned it out to a fellow astronomer and it was never returned. 🙁

  10. Am aflat aceasta pagina, dupa ce am cautat despre Unitron History Project pe Google.
    Se pare ca informatia dvs e foarte valoroasa, mai ales ca
    am mai gasit aici si despre ora, ora exacta, lucruri interesante
    si folositoare. Mult succes in continuare!

    I found this page after I searched on Google about Unitron History Project.
    It seems that your information is very valuable, especially as
    I found here on time, the exact time, interesting things
    and useful. Good luck!

  11. I have a 4 inch Unitron telescope with a Unihex eyepiece. It has an alti-azimuth mount and I was wondering if there is a way to motorize it so that it could automatically track objects like newer types of telescopes can.

    • Dear Chris,
      I have owned a 3″ altazimuth in mint condition for about 30 years. I’m getting ready to retire, and I have been searching for a 4″ altazimuth for several years. Would you accept an offer to purchase your 4″?
      Thank you for your time today!

  12. It galls me to say this but when I was a teen-ager, I did own a lovely 2.4″ altazimuth Unitron that, unfortunately, was stolen when we moved and in all the confusion, I did not realize that the theft had taken place until many months after. I was very ill at the time and once the theft had been discovered, I did not pursue the culprit which would probably not have been very hard. I hope, at least, that the thief got some pleasure out of the scope and simply did not steal it with the hope of reselling it. I have always regretted the theft, obviously, but even worse, I feel like an idiot for not pursuing the thief and recovering the telescope. I now own a Televue 4″ refractor which is a lovely instrument but I can never think of my old Unitron without a pang of regret. The scope was a birthday gift and at that time, which was 1965, the scope was priced at a measly $125.00. We moved in the early 1970’s and so I was able to get some use out of it and as you might expect, it performed superbly. I hate to think what the scope is worth now but someday, I hope to replace it but like I have already said, the cost must be, by this time, prohibitive. In any event, if the price is reasonable I would not completely rule out the idea of replacing it. But that might be too much to hope for. If anybody has this scope and is willing to sell it, maybe you could quote me a price and perhaps we can come to an agreement. I figure its worth a try!

    • Hello Alec,

      I too received the 2.4″ altazimuth Unitron for a present. This was a Christmas gift in 1969, and I was 17 years old. I will never forget the first time I viewed Jupiter through this telescope. It was a marvelous gift and incredibly affordable.
      I had to part with it after we had our first born.
      You should place a free wanted ad for it in Cloudy Nights if you have not already done so.

  13. Thank you so much for putting all this information together. I got an Unitron 142.3 model that belonged to my grandfather and I had some doubts about assembling it after so many years, since he was the one to get it ready to use when I was a kid. I was amazed to see that you have even the manuals. Again, thanks a million.

  14. Dave my friend you have created a wonderful depository of not only Unitron history but of the world wide subculture of passionate Amateur Astronomy . Our passion not only covers looking at these stars but often to the nomenclature of the wonderful equipment that it takes to get there !Thanks for your effort Dave and all the people that helped you along your way !
    mike hyrczyk

  15. on the left side I see a beautifull whell of occular

    do you have detail on this mecanical detail
    I am a A.T.M. and like this look

    meybe easy to reproduce

  16. I`m also own one! (a small one) : “Unitron” 6,5 And I Love It! …..And i allways Will! ….(Promise that)….

  17. What a great site! I had a 3″white and grey unitron telescope which I bought in pietermaritzburg, south Africa,in I’d guess about 1979?a little later I equipped myself with a red tasco 6″reflector (about 1981).even then the difference in the quality of the unitron vs tasco was notable.the unitron had a fantastic high quality finder,the tasco a tiny plastic lensed finder with a baffle right behind the front lense which must have given it effectively 10mm of apeture! sadly I long since gave both scopes away.

  18. I Have one of Those Wonderful Telescopes….a 6,5 /900 mm:s Beauty! ….Just Great!

  19. A nice Unitron 760 is now listed on eBay. Seems to be an attractive starting price of $285.

  20. Does Untitron still make telescropes??
    I bought my 2.4 Unitron telescrope in 1969 and it is a wonderful instrument.
    I am interested in buying a replaceament for the Sun Filter for my telescrop; the one that fits on the small viewing area of the front of the telescrope.

    • Hello Jack! First of all never ever use that eyepiece solar filter. Even when they were new they could crack and result in damage to your eye!!

      Secondly, Nihon Seiko, Unitron’s supplier, went out of business in the early 1990’s. You can still find used Unitron’s advertised on the Cloudy Nights forum or on Ebay.


  21. I believe I have one of the telescopes a polarex I would like to restore it will send photos

  22. What is the personal camera pictured on the camera clamp ring in the famous Unitron ad?

  23. I just inherited a massive Unitron from the 1950’s. Still trying to learn all of the parts.

  24. I have my grandfathers unitron model 114, 2.4 inch altazimuth refractor. Where might i find parts mainly the unihex rotary eyepiece selector? Are they available? I have the original wooden boxes, paperwork , instruction packet and packing list for it. Is ot worth anything? Any info would be awesome

  25. This resource is still a great read after all these years. Thanks for keeping it updated. One of these days I’ll have to come to NEAF to see the gang.

  26. Bonjour.
    Je réside en Belgique,ou la marque Polarex rappelle de nombreux souvenirs de rêves inaccessibles pour les modèles de 75 ou 100mm.N’evoquons même pas les modèles de 125mm réservés à des institutions.Possesseurs ou envieux de ces beautees,nous sommes resté marqué par leur esthétique.Ah,la ligne de ces f15!Et la qualité des equatoriaux.
    Aujourd hui,j’ai la chance de posséder deux lunettes de 100mm complètes,avec leurs caisses,et encore une de 60mm en caisse également.Je porte une affection particulière à l’une de ces 100mm que j’utilise régulièrement pour observer la lune,les étoiles doubles,les amas ouverts.
    Je n’ai que un regret,celui de ne pas avoir put acquérir une 125mm.Un jour,une personne m’en a proposée une.Helas,elle était dans un tel état que j’ai recule face au montant demandé.Je ne sais pas ce qu’elle est devenue,après son séjour Batave.
    Pour me console,j’ai assouvis mon envie en acquérant une lunette 135mm f15 de André Couder avec accessoires Clave.
    Ces merveilles à longues focales méritent d’être reconnues pour leurs qualités optiques comparativement à ces instruments contemporains à focales courtes qui ne sauraient que satisfaire les photographes.
    Au plaisir de vous lire sur ce site.

Leave a Reply

Your email address will not be published. Required fields are marked *