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Hi everyone I have recently purchased a celestron nexstar 8se as an upgrade from my 4se but when I looked at Mars today Mars was very fuzzy and very difficult to get perfect focus, if anyone could help me to see why this was I would be very grateful 

thank you 

joe 

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Joe - getting best focus can be tricky, especially at higher mags.  You won't really see much of Mars with the 8SE - it was at its best last year.  I used mine this evening and was only able to notice that Mars is looking somewhat gibbous at present.  Try looking at the Moon in the morning - you'll probably see great detail and be more satisfied.  

Doug.   

Edit:  If you can get sharp star images, there probably isn't anything wrong with 'scope.  Planets can be a little disappointing with some 'scopes.

Edited by cloudsweeper
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How many hours did you give the 8se to cool before you observed? What power were you observing at? Not giving the scope sufficient time to cool or pushing the magnification too high will result in unsatisfactory images. 

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I've often found that SCT's take an age to cool, which can mean that if you're taking it out into a cold winter night from a relatively warm house, it could easily take 3 hours or more to even begin working at its optimum. Even then I find them disappointing on planets, as they never seem to snap into sharp focus, but remain soft. Stellar targets don't fare much better either, as just when it looks like a star is going to snap into sharp focus, the image defocuses again. So to get the best from your 8SE it would pay to keep it at outside temperatures, and while during the warmer months, out of direct sunlight. 

Edited by mikeDnight
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  • 2 weeks later...

I had the same issue on the same scope the other week...just a fuzzy mess at high mag (8mm)and was still  just a speck of light @ 24mm. I can't say I've been impressed as yet by the 8se.

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2 hours ago, Skinnypuppy71 said:

I had the same issue on the same scope the other week...just a fuzzy mess at high mag (8mm)and was still  just a speck of light @ 24mm. I can't say I've been impressed as yet by the 8se.

There is quite a difference between a 24 and 8mm eyepiece, do you have anything between the two? Using an 8mm in an 8se will require very good atmospheric conditions, as well as properly cooling or insulating the telescope. 

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I was using a baader hyperion zoom eyepiece and tried everything in between....the seeing was not up to much in any of the focal lengths...I'm just assuming that the atmospheric conditions as you mentioned weren't great . oh and I had left the 8se in the shed most of the day and dew shield was on.lol.

Edited by Skinnypuppy71
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Ah, I should have guessed it was either end of a zoom you were talking about. With regards to cooling, I keep my 8" newt in a shed, have a primary cooling fan and I will still get it out to cool early if I think it will be clear and suitable for high power views. 

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