Unusual eyepiece

[Tweedledee]

Just added this eyepiece as no. 42 to my collection. ?

 

It is a Siberia 50mm 2" Erfle. It was very cheap and I'd never seen one before so I thought i'd check it out.

 

I can't find anything on the internet about this eyepiece, other than a suggestion that Siberia was a name under which Russian Tal scopes and eyepieces had been sold in the states for a while.

 

Does anyone know any more about Tal and the Siberia name or this eyepiece? Andy @tuckstar perhaps?

 

     

[BAZ]

At 50mm I would imagine that the would be a limited number of scopes that would work with, something like a long focal length SCT maybe, it would be interesting to find out what it did fit. Another one welcomed into the herd. ?

 

Edited June 25, 2018 by BAZ

[Tweedledee]

1 hour ago, BAZ said:

At 50mm I would imagine that the would be a limited number of scopes that would work with, something like a long focal length SCT maybe, it would be interesting to find out what it did fit. Another one welcomed into the herd. ?

 

I'll be trying it in a 120mm F9 refractor for a 5.5mm exit pupil. Abberations ought to be fairly well tamed at that ratio.

[tuckstar]

Sorry Pete, don't know a great deal about this one. I know some of the tal eyepieces can be a pain to focus due to how the scopes were set up with the focal point being further in than most. Tal marketed as siberia for the US market.

Found this thread on SGL,  https://stargazerslounge.com/topic/162409-whats-the-worst-eyepiece-youve-ever-used/?page=2

Edited June 25, 2018 by tuckstar

[Tweedledee]

Thanks Andy, that is the post I got my info from. That guy never got the big Erfle to focus in any of his scopes. I'm interested to find out just where the focal plane needs to be relative to this eyepiece. 

[tuckstar]

I know with my mates Tal he had to move the mirror up the ota to get normal eyepieces to focus. But that is a tal 1 and only 1.25 focuser.