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Any issues with using the Dakin 1.25x thread-on barlow with 24mm pan?

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3 replies to this topic

#1 ruachsheavens

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Posted 23 October 2021 - 09:28 AM

Hi all,

 

Just wondering of there would be any loss of optical quality or correction using these 2 pieces together?

 

thanks!



#2 Adam Long

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Posted 23 October 2021 - 12:23 PM

Given that the 24mm pan is maxing out the field stop for a 1.25" barrel, I'd expect vignetting to be obvious. But I've no direct experience with either item. 



#3 CeleNoptic

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Posted 23 October 2021 - 07:55 PM

I experimented with several Barlows and Barlow nosepieces combined with 1.25" eyepieces. My records are saying that both the  2x WO Binoviewer nosepiece and the GSO 1.25" 2x "Shorty" nosepiece screwed into 1.25" eyepieces showed vignetting with the 20mm ES68 so I have no doubt that vignetting will be even stronger in the 24mm Pan. For that you need a telecentric, like ES Focal Extender or TV Powermate. Alternatively, a 2" telenegative Barlow like the AT 2x Apochromatic should work, but I'm not sure if you'll want that weight in your focuser.


Edited by CeleNoptic, 23 October 2021 - 08:15 PM.

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#4 JAC51

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Posted 24 October 2021 - 03:53 PM

I am in a position to be uniquely unhelpful to your question. I have the x1.25 Magic Dakin , the x1.5 MDB and a 24mm panoptic. But my Barlows have the Brandon thread and so I can’t attach them to the pan. I have though used them with a 32mm Brandon which has field stop of 25mm without me noticing any vignetting, still not up to the 27mm of the Pan of course but still I think larger than the 20mm ES68.




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