Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Who supplied (ortho) glass to Tani?

This topic has been archived. This means that you cannot reply to this topic.
2 replies to this topic

#1 hottr6

hottr6

    Skylab

  • *****
  • topic starter
  • Posts: 4,171
  • Joined: 28 Jun 2009

Posted 10 March 2016 - 04:05 PM

My quest for obscure information on Japanese optics continues.  The subject of this thread is to ask who supplied Tani-san with glass?

 

In an older thread, Sheldon Faworski stated that Carton supplied Tani with glass (and Towa, Vixen, Celestron, Edmund Sci., Tele-Vue, etc) and he, of all of us,  should know because he sold Carton stuff.

 

CN wisdom suggests that Carton stamped some of their eyepieces with a "Circle-Minus".

 

I collect volcano tops, and recently spent a pleasant evening with these two:

IMG_7116.JPG

On the left is a "Circle-Minus", and on the right, a "Circle-T".  But they are utterly different!  First difference noted is the bevel, knurling and location of the eye lens in the volcano tops.  The engraving is also different.  And heck, the view was utterly different, with the Circle-Minus providing a much crisper field stop and view right across the slightly larger FOV than the "Circle-T", and the point at which they focus differ by several millimeters.  Some of this can be explained by the different construction when viewed from below the eyepiece:

IMG_7117.JPG

These are two very, very different eyepieces.

 

I have not (yet) taken them apart, so cannot tell if I am looking through an Abbe ortho or symmetrical ortho ("Plossl-lite").

 

Discussion

- If Carton supplied Tani with glass, then Carton may have had more than one formulation for orthoscopic quality available to resellers.

- If Carton supplied Tani with glass, then Tani may not have always selected the premium formulation.

- If Tani did pick and choose quality, then "Circle-T" is no guarantee of a premium orthoscopic.

- If Tani did pick and choose quality, then they may have had more than one source of glass.

 

Conclusion

Vintage volcano top orthos are no guarantee of premium vintage eyepieces.  I suggest this conclusion may extend to Kellner designs as well.


Edited by hottr6, 10 March 2016 - 04:07 PM.


#2 Bomber Bob

Bomber Bob

    Hubble

  • *****
  • Posts: 19,535
  • Joined: 09 Jul 2013

Posted 10 March 2016 - 04:47 PM

Pretty sure Tani used multiple suppliers.  On a Meade Research Grade thread, I posted that my first RG OR7 purchase had the Circle T JAPAN sticker on the barrel, rather than the cap, so I removed it.  Others in that post said that Nikon supplied glass for the RG Series, and I don't doubt it - my Orthos are still great eyepieces after 30+ years.  University Optics states that Ohi supplied glass for their Circle T Orthos back then, and the new HD Orthos now.  I bought a set of those, and they are as good as the RGs.

 

I have 3 volcano top OR12.5's.  All are Tani / Circle T, one is branded Celestron, one Edmund, and one unbranded.  They're all very good, but the unbranded has green coatings, and is the best of the trio.

 

So, looks like Carton, Ohi, & Nikon supplied glass to Tani, and there were probably many others.  I bet the supplier depended on the vendor's requirements for Tani, like the price range(s).



#3 hottr6

hottr6

    Skylab

  • *****
  • topic starter
  • Posts: 4,171
  • Joined: 28 Jun 2009

Posted 10 March 2016 - 05:52 PM

Pretty sure Tani used multiple suppliers.  On a Meade Research Grade thread, I posted that my first RG OR7 purchase had the Circle T JAPAN sticker on the barrel, rather than the cap, so I removed it.  Others in that post said that Nikon supplied glass for the RG Series, and I don't doubt it - my Orthos are still great eyepieces after 30+ years.  University Optics states that Ohi supplied glass for their Circle T Orthos back then, and the new HD Orthos now.  I bought a set of those, and they are as good as the RGs.

 

I have 3 volcano top OR12.5's.  All are Tani / Circle T, one is branded Celestron, one Edmund, and one unbranded.  They're all very good, but the unbranded has green coatings, and is the best of the trio.

 

So, looks like Carton, Ohi, & Nikon supplied glass to Tani, and there were probably many others.  I bet the supplier depended on the vendor's requirements for Tani, like the price range(s).

That dovetails with my thoughts as well.

 

I think what it means for buyers is buy 'em, try 'em, and if they are not up to snuff, sell 'em (but please state reasons for doing so).




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics