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SkyMax 150 focus issue?

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6 replies to this topic

#1 Bob Dunn

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Posted 24 October 2021 - 12:58 PM

Set up my new SkyMax 150 today with the kit 28mm LET eyepiece. When aimed at a distant tree, all I see is a tiny (2-3mm) bright spot in the eyepiece. Any ideas what I’m doing wrong?

P.S. I’m a newbie.



#2 michael8554

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Posted 24 October 2021 - 02:14 PM

Be prepared to put many wrist turns into the focus knob on the back of the scope to get focus.

 

A Distant Tree may be too close for the scope to focus


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#3 Bean614

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Posted 24 October 2021 - 02:42 PM

Yup!  You have a long focal length scope there.  Focus on something a half mile away!



#4 Bob Dunn

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Posted 25 October 2021 - 03:37 PM

Got it! Thanks!



#5 Asbytec

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Posted 04 November 2021 - 07:21 AM

Set up my new SkyMax 150 today with the kit 28mm LET eyepiece. When aimed at a distant tree, all I see is a tiny (2-3mm) bright spot in the eyepiece. Any ideas what I’m doing wrong?
P.S. I’m a newbie.

Hmm, a 2 to 3mm bright spot you say? It could be the exit pupil of the telescope formed and appearing over the eyepeice eye lens. A 28mm eyepeice will form an exit pupil of about 2.3mm in diameter with your 150mm aperture at 64x.

If so, then that's completely normal. All you gotta do is put your eye on it to see the telescope image of the tree and everything else. The exit pupil squeezes the telescope's light through your iris when you put your iris on or very near the eyepeice eye lens.

Edited by Asbytec, 04 November 2021 - 07:25 AM.


#6 Bob Dunn

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Posted 04 November 2021 - 08:58 AM

Asbytec,

Of course!

I’ve looked through my other telescope before, but had never noticed the exit pupil shining on the glass. I finally clued in a few days ago. I’m seeing images now. It does take an unusual number of turns on the focus knob, as others have said.

Thanks very much for your comments.

Bob


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#7 Asbytec

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Posted 04 November 2021 - 10:22 AM

Very cool. :)




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