1. 

   Roel Standard User

   Joined:

   Dec 18, 2016

   Messages:

   1

   Hi,
   
   I would like to know the combined backfocus distance of the above.
   My telescope (Esprit 100) has 63 mm backfocus so I need to figure out what size adapter I need to make.
   Based on this link I concluded the answer is 54.6mm so I had an 8.4 mm adapter made. However, the results are not good (stars shape problems in corners).
   
   Thx, Roel

    

   Roel, Sep 11, 2017

   #1
2. 

   Doug Staff Member

   Joined:

   Sep 25, 2014

   Messages:

   9,967

   The information is in the Downloads section of the STF-8300 page (ST and STF are the same).
   
   Copied here for your convenience:
   
   

    

   Doug, Sep 11, 2017

   #2

   KLee02 likes this.

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