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Are there any eyepieces with 5 lenses

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#51 luxo II

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Posted 22 October 2020 - 02:31 AM

Optics from the military and gun fraternity are aren’t all that great - the primary need was to centre weapon on target - and a wide field is desirable. Supreme image quality across the field was never a high priority.

Edited by luxo II, 22 October 2020 - 03:04 AM.

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#52 25585

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Posted 22 October 2020 - 02:44 AM

No, sorry, the latest version is an original design by Yuri Kletsov and/or Rusinov, Kletsov wrote TAL designs about eyepieces but the document was sold only at 200 copies. Bill Paolini reviewed them in 2013, they have around 46.5° (Ernest SPB) and 51° (Bill), depends on their focal length and instrument pairing. It uses CTK3 LZOS glass (light lanthanum crown) for the crown and maybe TF1 (similar to Schott SF2) flint

https://www.cloudyni...er-plössl-r2844
 

see http://www.sibran.ru...g/INTER/161085/

Klevtsov Yu.A.
Novosibirsk: Publishing house of the SB RAS , 2014 , 312 p. , Circulation 200 , ISBN 978-5-7692-1343-4

I could'nt find version of this book. I believe @Vla had extrapolated some datas from this book, he put infos about the TAL barlow design on his site and also somes about the recent TAL wide field. 

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#53 j.gardavsky

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Posted 22 October 2020 - 04:05 AM

No, sorry, the latest version is an original design by Yuri Kletsov and/or Rusinov, Kletsov wrote TAL designs about eyepieces but the document was sold only at 200 copies. Bill Paolini reviewed them in 2013, they have around 46.5° (Ernest SPB) and 51° (Bill), depends on their focal length and instrument pairing. It uses CTK3 LZOS glass (light lanthanum crown) for the crown and maybe TF1 (similar to Schott SF2) flint

https://www.cloudyni...er-plössl-r2844
 

see http://www.sibran.ru...g/INTER/161085/

Klevtsov Yu.A.
Novosibirsk: Publishing house of the SB RAS , 2014 , 312 p. , Circulation 200 , ISBN 978-5-7692-1343-4

I could'nt find version of this book. I believe @Vla had extrapolated some datas from this book, he put infos about the TAL barlow design on his site and also somes about the recent TAL wide field. 

Hello Myriam, and thank you for your input.

 

Yesterday night, I have seen the original TAL Plössl f=25mm (with the inscriptions in Russian), not the export version as described by B. Paolini, offered on the eBay for 40.00 EUR

 

The first striking difference is, the eye lens in the TAL is significantly larger than on the Zeiss. The second difference is in the multicoatings. These both are indicators of the optics formula changed and adapted to the LZOS glass materials.

If TAL takes the lanthanum glass, it's good, but the lanthanum glass has been used by Leitz and Zeiss decades ago as a replacement for the thoriated glass materials.

 

Here we are attributing the legacy of the modern Plössls designs to Zeiss,

and not to the manufacturers in China or Russia, even if the TAL Plössl and the Chinamakes called as Plössl or Super Plössl, are much more widespread in our hobby astronomy.

 

Best,

JG


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#54 MartinPond

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Posted 22 October 2020 - 08:32 AM

Optics from the military and gun fraternity are aren’t all that great - the primary need was to centre weapon on target - and a wide field is desirable. Supreme image quality across the field was never a high priority.

 

Guns (as in sporting  and many light military guns) are in their own kettle of fish.

They usually do not have high afov(by this salon's standards), but they have

 massively long eye relief.   Not at all like a tank or a submarine.

 

Sniper teams today are usually the 50-BMG shooter with high-power scope

   and the spotter, who has 12--16X wide afov to locate the target and

   locate the hit.  Both have high resolution.

    That would be the reverse of the above assertion, which seems more appropriate

      for artillery or mortars.

 

As far as old military, that varies a lot depending on the application.


Edited by MartinPond, 22 October 2020 - 08:33 AM.

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#55 25585

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Posted 22 October 2020 - 09:53 AM

Hello Myriam, and thank you for your input.

 

Yesterday night, I have seen the original TAL Plössl f=25mm (with the inscriptions in Russian), not the export version as described by B. Paolini, offered on the eBay for 40.00 EUR

 

The first striking difference is, the eye lens in the TAL is significantly larger than on the Zeiss. The second difference is in the multicoatings. These both are indicators of the optics formula changed and adapted to the LZOS glass materials.

If TAL takes the lanthanum glass, it's good, but the lanthanum glass has been used by Leitz and Zeiss decades ago as a replacement for the thoriated glass materials.

 

Here we are attributing the legacy of the modern Plössls designs to Zeiss,

and not to the manufacturers in China or Russia, even if the TAL Plössl and the Chinamakes called as Plössl or Super Plössl, are much more widespread in our hobby astronomy.

 

Best,

JG

Some of my TAL 25 Plossls  symmetricals are as in the photo below. They were OE kit with TAL telescopes, and are also the eyepiece used in TAL 50mm finder scopes.  Baader used them with a bayonet adapter, as for Zeiss Diascope spotting scopes.

 

Original TAL F=25 were not 31.7mm fit. They were fine for TAL scope focusers, which were broader than 31.7mm (so can be too loose for 31.7). Current TAL 25mm are in 31.7mm diameter nosed barrels. Like 28mm RKE eyepieces, they give an immersive, floating view.  

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Edited by 25585, 22 October 2020 - 09:55 AM.

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#56 j.gardavsky

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Posted 22 October 2020 - 10:46 AM

Some of my TAL 25 Plossls  symmetricals are as in the photo below. They were OE kit with TAL telescopes, and are also the eyepiece used in TAL 50mm finder scopes.  Baader used them with a bayonet adapter, as for Zeiss Diascope spotting scopes.

 

Original TAL F=25 were not 31.7mm fit. They were fine for TAL scope focusers, which were broader than 31.7mm (so can be too loose for 31.7). Current TAL 25mm are in 31.7mm diameter nosed barrels. Like 28mm RKE eyepieces, they give an immersive, floating view.  

Thank you very much,

 

this looks like what I have seen on the eBay,

JG


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#57 Astrojensen

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Posted 23 October 2020 - 10:38 AM

Optics from the military and gun fraternity are aren’t all that great - the primary need was to centre weapon on target - and a wide field is desirable. Supreme image quality across the field was never a high priority.

And yet some of those eyepieces perform absolutely insanely well, especially in long focal ratio refractors, but sometimes also in very short ones.

 

 

Clear skies!

Thomas, Denmark


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#58 25585

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Posted 23 October 2020 - 10:44 AM

And yet some of those eyepieces perform absolutely insanely well, especially in long focal ratio refractors, but sometimes also in very short ones.

 

 

Clear skies!

Thomas, Denmark

The EP.3 here     https://irpoyser.co....-and-eyepieces/

 

is an example of such.  Ex NATO but very good for its price.

 

It is a 1-2-1 Konig according to the Brayebrook article "Unusual Eyepieces".


Edited by 25585, 23 October 2020 - 10:57 AM.

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#59 j.gardavsky

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Posted 23 October 2020 - 01:14 PM

The EP.3 here     https://irpoyser.co....-and-eyepieces/

 

is an example of such.  Ex NATO but very good for its price.

 

It is a 1-2-1 Konig according to the Brayebrook article "Unusual Eyepieces".

The (1 - 2 - 1 ) lenses group is inside the widespread Leica L Plan 8x/25 (Glasses) #506806 (f=32mm) for the L series microscopes with the binoviewer,

and it is one of my favourite "long" eyepieces for the large low surface brightness objects,

 

Leica Microsystems Eyepieces.jpg

 

The first lens does the field flattening for the otherwise classic (2 - 1) König.

 

Best,

JG
 


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#60 droid

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Posted Yesterday, 05:44 PM

Symmetrical. But....

My Meade is a standard symmetrical.

 

So not to super? , lol



#61 lylver

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Posted Yesterday, 05:49 PM

Some of my TAL 25 Plossls  symmetricals are as in the photo below. They were OE kit with TAL telescopes, and are also the eyepiece used in TAL 50mm finder scopes.  Baader used them with a bayonet adapter, as for Zeiss Diascope spotting scopes.

 

Original TAL F=25 were not 31.7mm fit. They were fine for TAL scope focusers, which were broader than 31.7mm (so can be too loose for 31.7). Current TAL 25mm are in 31.7mm diamtop qeter nosed barrels. Like 28mm RKE eyepieces, they give an immersive, floating view.  

Yes this is the old version, which is viewed as better for the 25mm focal length. I never put a hand on it.




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