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

Need help to id this eyepiece

  • Please log in to reply
6 replies to this topic

#1 photiost

photiost

    Mercury-Atlas

  • *****
  • topic starter
  • Posts: 2,820
  • Joined: 14 Dec 2006
  • Loc: Montreal, Canada

Posted 21 March 2020 - 07:33 PM

Posted this in the eyepiece forum and so far nada  ...

 

Found this eyepiece while sorting out my Astronomy stuff, can't remember when I got it ... possibly at the Stellafane swap table a few years back.

 

In any case it has a AFOV of around 65 degrees and its between 20 to 25 mm f/l (by my estimates), has the Japan/Circle T mark  

 

I am thinking early Erfle ... maybe a Meade ?

 

Has anyone seen something similar so we can id ?  

Attached Thumbnails

  • Erfle IMG_1970.JPG
  • Erfle IMG_1972.JPG
  • Erfle IMG_1973.JPG

  • astro140 and Terra Nova like this

#2 ngc7319_20

ngc7319_20

    Apollo

  • *****
  • Posts: 1,251
  • Joined: 25 Oct 2015
  • Loc: MD

Posted 21 March 2020 - 09:43 PM

Is the surface of the eye lens flat or concave?

 

If you shine a pen light (or similar) in the top, how many reflections of the light do you see inside the eyepiece?  What colors are the reflections?  This can give some clues about the internal construction.

 

What does the input end look like -- is there a lens right at the bottom?  Or just a field stop part way up inside?

 

The eye lens is quite large... interesting...  The bare aluminum top makes me wonder if someone machined it down to get more eye relief.


Edited by ngc7319_20, 21 March 2020 - 09:48 PM.

  • photiost likes this

#3 Bomber Bob

Bomber Bob

    Hubble

  • *****
  • Posts: 16,845
  • Joined: 09 Jul 2013
  • Loc: The Swamp, USA

Posted 21 March 2020 - 10:38 PM

The body style reminds me of the old Orion Ultrascopics.  1970s Tani, should be good no matter the brand or importer.


  • photiost likes this

#4 Terra Nova

Terra Nova

    ISS

  • *****
  • Posts: 21,906
  • Joined: 29 May 2012
  • Loc: Under the Blue Moon of Kentucky

Posted 22 March 2020 - 08:59 AM

The body looks to me like the Parks 32mm Erfle. That is one that I let go of that I regret now. Since I nolonger have it, I can’t check the eyelens to see if it’s concave. I have Orion 30mm and 35mm Ultrascopics and a circle T 32 mm Erfle and it’s none of those three.


  • photiost and Bomber Bob like this

#5 photiost

photiost

    Mercury-Atlas

  • *****
  • topic starter
  • Posts: 2,820
  • Joined: 14 Dec 2006
  • Loc: Montreal, Canada

Posted 22 March 2020 - 10:13 AM

ok under closer inspection the top eyelens seems relatively flat  (to me ) and the bottom seems slightly concave 

 

I also measured and yes it is closer to 32mm 

 

Eyepiece has a nice feel to it and the AFOV edges are sharp.

 

If it stays clear tonight will take it outside and see what it can do against the 30mm Ultima + 32mm TVue

 

cheers  

Attached Thumbnails

  • aa erfle IMG_1983.JPG
  • aa erfle IMG_1984.JPG
  • aa erfle IMG_1985.JPG

  • Terra Nova and Bomber Bob like this

#6 Bomber Bob

Bomber Bob

    Hubble

  • *****
  • Posts: 16,845
  • Joined: 09 Jul 2013
  • Loc: The Swamp, USA

Posted 22 March 2020 - 11:05 AM

Sheldon (MASILMW) sells unbranded eyepieces, so he may be able to ID yours.

 

However, one of the Tani volcano-tops that I gave away was unbranded -- had a space reserved for Edmund, UO, etc.


  • photiost likes this

#7 ngc7319_20

ngc7319_20

    Apollo

  • *****
  • Posts: 1,251
  • Joined: 25 Oct 2015
  • Loc: MD

Posted 22 March 2020 - 02:08 PM

Yes, maybe someone with an early Parks / Orion / University Optics catalog can look it up.  Tani tended to put their labels around the glass at the top, which appears to have been machined off here.  It may have been some sort of "volcano top" and they machined off the extra metal at the top, so they could wear glasses with it.

 

Something in the numbers is wrong. It won't be 1.25" barrel, 32mm FL, and 65 degree AFOV. Perhaps it is 25mm and 65 AFOV.  The mechanical length doesn't necessarily tell you the focal length.


Edited by ngc7319_20, 22 March 2020 - 04:00 PM.



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