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Celestron Nexstar 4SE focus

beginner Celestron
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4 replies to this topic

#1 MarisinOZ


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Posted 02 July 2020 - 11:42 PM

I dragged the scope out of the bottom of my family's wardrobe and decided to put it to use. It's been sitting there packed up for quite a while, hardly ever been used.


I cannot achieve focus. (Yes, I've read the manual and I believe I'm following correct procedure). I've gone the full range of adjustment with no apparent change to the image.


I have no astronomical experience at all (I do use a spotting scope) and I'm wondering if I've missed the bleeding obvious. (Lens cap is off)


Light is coming through, when I point at a tree I see green, white or blue when aimed at the sky.

#2 jimr2


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Posted 03 July 2020 - 12:19 AM



If you have more than one eyepiece for the scope, try using all of them in it to see if you can achieve focus with any of them, or none of them? If you can't focus with any of them, then try moving or holding the eyepieces a little ways out of the eyepiece holder in case you don't have enough "back focus" to achieve focus on this scope--in which case you might need a short extension tube to insert into the eyepiece holder, then insert the eyepiece(s) into the other end of it. If the focus improves as you screw in the eyepiece tube towards the telescope, then that's a more problematic issue, but usually isn't the case.


Again, try different eyepieces in the scope, and do try to focus on something on the ground in the daytime, that's a quarter mile or more away from you. Good luck!



#3 PNW


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Posted 03 July 2020 - 12:27 AM

Using a diagonal is another obvious. That is necessary to get the proper focal length. Another is spinning the focus knob too fast. It's easy to blow past the focus point.

#4 doublevodka


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Posted 03 July 2020 - 02:25 AM

I have the same model so can hopefully help.


Firstly, pick the lowest magnification eyepiece you have if you are trying to focus on something in the daytime, the highest number in mm.


Secondly, go slowly with the focus knob, it may seem a little daft but the scope will go from out of focus, to focused, to out of focus again very quickly, so slowly slowly is the key waytogo.gif

#5 phillip


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Posted 03 July 2020 - 02:36 AM

Yes also have that vary scope.


Most already covered.


Simply might be trying to focus on objects too close, aim for something a mile away as mentioned.


Also covered try different eyepieces.


Moon a great object to try at the start, things should eventually work.


I actually have an eyepiece high power that simply doesn't focus sharp on planets at all. So yes use different eyepieces!




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