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backfocus for c11 with a reducer and asi2600mc

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#1 bujin9

bujin9

    Sputnik

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Posted 30 May 2020 - 06:27 PM

Hi all...

quick backfocus question..

C11 with a 6.3 reducer, attached is the asi2600mc pro....105mm?

thanks in advance,

Joe



#2 Umasscrew39

Umasscrew39

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Posted 31 May 2020 - 05:16 AM

Hi Joe

 

I have a C11" EdgeHD with the asi2600mc pro and a .7x reducer.  The backfocus should be 146mm from the back threads of the reducer to the sensor with this setup.  How did you come up with 105mm?



#3 Tapio

Tapio

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Posted 31 May 2020 - 05:23 AM

The back focus of older reducer for classical SCT is 105mm.

Different from 0.7x reducer for EdgeHD.



#4 bujin9

bujin9

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Posted 31 May 2020 - 10:57 AM

Yes, it's the classic SCT with the older reducer. Was able to achieve focus last night but unfortunately, clouds plagued me all night so no imaging got done.




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