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10” Carl Zeiss Refractor

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#1 Old Will

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Posted 27 June 2020 - 02:18 PM

There is a 10” Carl Zeiss Refractor for sale on Ebay.  I would like to know if anyone knows about the possibility to make a flourite 4" lens that is  mounted about 3 feet from the tailpiece to produce Apochromat quality images?  The owner says this scope has one made by Roland Christen.

The objective is F/16, but if I understand correctly with the correcting lens it is about F/13,  Any possibility of such, and any designs would be appreciated as I have a 9.5" Achromat blanks set, which would be better than the triple folded F20 I have been contemplating.

    Many thanks from   Old Will



#2 lee14

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Posted 27 June 2020 - 02:46 PM

you might take a look here, if you've missed this thread: 

 

https://www.cloudyni...14328-zeiss-10/

 

Lee


Edited by lee14, 27 June 2020 - 03:20 PM.


#3 Astroman007

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Posted 27 June 2020 - 02:46 PM

Link?



#4 Astroman007

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Posted 27 June 2020 - 02:47 PM

you might take a look here, f you've missed this thread: 

 

https://www.cloudyni...14328-zeiss-10/

 

Lee

Posted at the same time. Well beyond my budget, despite it being the 'bay.


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#5 vahe

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Posted 27 June 2020 - 03:30 PM

Somewhat related;

.

This was a loooong time ago, Roland produced a reducer for a Zeiss AS 8" F/15 refractor, the reducer was placed inside the tube somewhat similar to a Petzval system, this configuration resulted in a F/10 telescope with improved CA.

.

Roland placed an ad in Sky&Tel for this scope asking $5000.00, I am still kicking myself for not buying this refractor, the weight and size scared me.

.

Vahe


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#6 Stewc14

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Posted 27 June 2020 - 10:15 PM

I often wondered about the folded refractor . I found a 12 " ziess set in Finland . I have been waiting for a friend to verify and send pics. I taught some classes at the college there and made some connections.There is another in Estonia I've been told . I have been told it has a correcting lense made for it. I am wondering who made it.I will report back if it turns into a reality.
That 10 inch is huge looking.I have a 9. " that I move in and out every night that it is clear enough.All my other scopes and mounts are still crated awaiting the observatory build.
I would love to look through a larger refractor. I just sold a 6" f13 completely hand made. I wish I still had it. But alas, I had to sell 4 scopes and save the money in case a tak. Em 500 or 400 comes back up for sale.
I wonder if Roland would ever rework any other makers glass? I have a project and maybe another down the road. Pipe dream ,,,,Probably,,,

#7 Paul Morow

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Posted 28 June 2020 - 01:24 PM

Somewhat related;
.
This was a loooong time ago, Roland produced a reducer for a Zeiss AS 8" F/15 refractor, the reducer was placed inside the tube somewhat similar to a Petzval system, this configuration resulted in a F/10 telescope with improved CA.
.
Roland placed an ad in Sky&Tel for this scope asking $5000.00, I am still kicking myself for not buying this refractor, the weight and size scared me.
.
Vahe



I remember that Zeiss refractor that Astro-Physics brought out to AstroFest in the late 1990s. It was an impressive instrument, but the lens took a long while to reach equilibrium on a hot Summers night. During the early morning hours I don't think the lens was able to totally cool and images at about 285x (7mm Nagler, if I remember correctly) were still a little soft.

Attached Thumbnails

  • AstroPhysics_Ziess8f10.jpg
  • AstroFest_Ziess8f10.jpg

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#8 vahe

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Posted 28 June 2020 - 01:43 PM

I remember that Zeiss refractor that Astro-Physics brought out to AstroFest in the late 1990s. It was an impressive instrument, but the lens took a long while to reach equilibrium on a hot Summers night. During the early morning hours I don't think the lens was able to totally cool and images at about 285x (7mm Nagler, if I remember correctly) were still a little soft.

 

I do recall a discussion regarding the corrector/reducer lens installed inside the tube, from what I recall one of the special glasses required to construct this corrector/reducer was somewhat unstable and highly susceptible to atmospheric attacks and would degrade over time. Do not remember if this was a comment from Roland or someone else.

.

Vahe



#9 Echolight

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Posted 28 June 2020 - 01:49 PM

Somewhat related;

.

This was a loooong time ago, Roland produced a reducer for a Zeiss AS 8" F/15 refractor, the reducer was placed inside the tube somewhat similar to a Petzval system, this configuration resulted in a F/10 telescope with improved CA.

.

Roland placed an ad in Sky&Tel for this scope asking $5000.00, I am still kicking myself for not buying this refractor, the weight and size scared me.

.

Vahe

The size and weight of the mount would scare me.



#10 Daniel Mounsey

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Posted 28 June 2020 - 05:09 PM

There is a 10” Carl Zeiss Refractor for sale on Ebay.  I would like to know if anyone knows about the possibility to make a flourite 4" lens that is  mounted about 3 feet from the tailpiece to produce Apochromat quality images?  The owner says this scope has one made by Roland Christen.

The objective is F/16, but if I understand correctly with the correcting lens it is about F/13,  Any possibility of such, and any designs would be appreciated as I have a 9.5" Achromat blanks set, which would be better than the triple folded F20 I have been contemplating.

    Many thanks from   Old Will

It’s still F16 with the corrector




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