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Questar back focus

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3 replies to this topic

#1 colum

colum

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Posted 16 September 2019 - 12:36 AM

I put up my old old 3 1/2 up for sale and there were no offers ..it has a few problems but works fine for what I need

 

I'm going to buy a used camera and start taking pictures but I would appreciate it if someone would advise me on how or where I can find an adapter to go from the visual to a camera and does the camera need to be moved back and forth for its own focusing in addition to the Questar rack and pinion.

I'm really excited about this and I'm glad no one made an offer

 

I will post my best picture when I get the setup ...I hope someone can advise me...Thanks...Jeff



#2 Optics Patent

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Posted 16 September 2019 - 08:19 AM

DM me with your email address. I have an extra coupling set in mint condition for half of new price. (I have two, actually in case anyone else wishes to have one).

#3 RobertPettengill

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Posted 17 September 2019 - 05:18 AM

You can put a camera in place of the eyepiece on the Questar as you can on any scope and it may be necessarry to do that for targets near the celestial poll. Most of the time you can use the axial port for the camera and keep your eyepiece in place. When you use the control box lever to view the finder through the eyepiece, the axial port mounted camera will receive light from the telescope.
It is quite difficult to get the focus the same for the camera and main telescope eyepiece view. It takes an eyepiece extender. It’s much easier to just refocus.
I’ve put together everything you need to know about axial port adapters for different camera configurations at:

http://astronomy.rob...eraConnect.html
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#4 BillHarris

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Posted 17 September 2019 - 03:15 PM

And the camera remains "fixed" in the axial adapter and does not move to focus. The Questar optical system moves the primary mirror to adjust the focal point behind the mirror at either the eyepiece or the axial adapter.


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