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#1 Jack160219

Jack160219

    Sputnik

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Posted 25 May 2020 - 11:36 AM

I need help figuring what I need to set up. I’ve got a Celestron 9.25 SCT with a 6.3 reducer which is a 2 in diameter.

 I want to do prime focus and attach a zwo asi 120. So the t adapter will have to screw into the reducer and I wanted everything in a straight line

rather than using a 2 in angle. Do they have a 2 in to 1.25 in adapter? Would this work? What’s the best way to do this with a reducer? I’m 

pretty new at this ,so any help would be appreciated. Thanks, jack



#2 Tapio

Tapio

    Mercury-Atlas

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Posted 25 May 2020 - 11:45 AM

What are you going to image ?

You are having pretty narrow fov: 17.46' (about half of moon diameter).

Also you need to have such extensions that sensor is 105 mm from reducer back.

Closer to reducer and you get less reduction (from the nominal f/6.3).



#3 Manitu

Manitu

    Lift Off

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Posted 27 May 2020 - 10:57 AM

You could use a 2" to T2 reducer. They are available (i.e. Baader Planetarium offers one: https://www.baader-p...cal-length.html). And then you attach T2 extensions of appropriate length to reach the required backfocus of your reducer. So you would need 91mm length of T2 extensions (as 12.5 from cam and 1.5 from adapter are 14mm).

I would suggest to use one vario extension with variable length setting so you can adjust your length backfocus to achieve the best result.

But keep in mind that the FOV is really small and you could get trouble if you want to use plate solving.

 

CS Tom


Edited by Manitu, 27 May 2020 - 11:01 AM.



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