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Cannot achieve focus

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5 replies to this topic

#1 frich1230

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Posted 23 September 2022 - 04:53 PM

Hi all

So I wanted to use my new 6” Skywatcher Newt
Collimated using a laser
Used a 38mm 2” eyepiece I cannot achieve focus
Tried an extension tube still no good

Any ideas are appreciated

Frank R

#2 photoracer18

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Posted 23 September 2022 - 06:10 PM

It likely needs to go farther in not farther out. That is the case with most reflectors. Its possible a 1.25" eyepiece of 38mm might work. If you bought the scope new it should have come with a 10mm and probably a 25mm. Those 2 sizes focus closer to the optical tube than a 38mm one.


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#3 Bean614

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Posted 23 September 2022 - 06:13 PM

^^^^^  This!  ^^^^^^^



#4 MellonLake

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Posted 23 September 2022 - 08:10 PM

You can try tightening all the primary mirror alignment knobs down until the bottom and then back them off half a turn and realign the primary. This might help.

#5 MellonLake

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Posted 23 September 2022 - 08:13 PM

Fyi if you point the telescope at the moon (yes I realize it is a new moon now) you can determine bwhete the focal plane is by using a piece of tissue paper in the focuser. When the moon comes to focus on the tissue paper, that is the prime focus. The lower elements of the eyepieces need to be at or near the prime focus.

#6 SteveG

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Posted 24 September 2022 - 03:45 PM

I had a GSO 8” f6 dob, and everyone that had the same dob required more outward focus to get a 2” eyepiece to work.

 

What 6” Skywatcher scope do you have?

 

PS, you should list your scopes your signature.




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