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Well, I did it! Bought the Nexstar 8SE.

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#26 Tony from Tulsa

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Posted 20 November 2012 - 05:33 PM

As far as your problem with higher magnification, was the scope at thermal equilibrium? If not it will have a similar effect as poor seeing.

James

Doubtful that it was. We got home at 7:30 and I rushed it outside to try it out. *BUT*, by the time I got it aligned after four slow tries, it was about 8:00 or 8:15, and I observed jupiter for about a half hour. I think I was expecting a giant HD view of Jupiter through my new scope, haha! The problem my inexperience and this forum is the best place I know to remedy that. I'm ordering a dew shield and possibly another eyepiece. Perhaps a 5mm or 6mm? One other thing: the scope seemed a little "shaky"-very slight, but noticeable. Maybe the tube is a little front heavy on the mount. Everything is good and tight, so I'll tweak that backward just a smidge and see if the helps. Thanks again to all for the help!

#27 Tel

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Posted 20 November 2012 - 06:15 PM

Hi Tony,

I think you'll find that you need a little longer than half to three quarters of an hour to allow your 'scope to equilibrate its internal temperature to that of the evening air if it were stored previously in the house. A safe bet is probably an hour or more before trying to view the detail presented by planets, although low magnification observations can, in the meantime, produce reasonable views: while you wait so to speak !

Secondly, I would advise you strongly, not to invest in any EP of such short focal length. The 8SE is a great 'scope but cannot really do a 5-6mm EP justice, except perhaps on that one clear night one experiences once every ten years !

No, if you want to obtain the highest magnification possible to suit the aperture of your 'scope, then select nothing shorter than somewhere between 8-10mm.

Finally, as to the "shakiness" you mentioned, the 8SE is claimed to be a little less stable on its mount than the comparable 6SE. In other words, the 8SE set-up shows signs of a slight overload leading to the effects you have noted.

A couple of ways though to make the set-up a little more stable, relate to lowering the tripod (i.e. the centre of gravity of the 'scope), and additionally, hanging a weight from the central spreader, (some use their power tanks, others a sand sack).

You can also invest in a motorised focuser which allows focusing untouched by hand, thus eliminating any shake which is otherwise inevitable when focusing.

Hoping this helps,
Best regards,
Tel

#28 hopskipson

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Posted 20 November 2012 - 06:19 PM

If you had a hard time focusing the 13 mm then going shorter will be harder.

James

#29 Peter9

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Posted 21 November 2012 - 05:17 AM

Hi Tony,

A 8mm X 24mm zoom eyepiece is a good way to go. I use one as my main eyepiece and find it a joy.

Regards. Peter.

#30 Tel

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Posted 21 November 2012 - 06:20 AM

Hi Tony,

I fully support Peter's suggestion. The Baader Hyperion 8mm X 24mm parfocal EP is certainly a firm favouritye amongst many Nexstar owners on this forum.

It will give you a wide range of EP focal lengths and hence magnifications via its "click-stop" operation.

True, it's not exactly cheap at ca. $290, but perhaps consider that this single unit contains at least five fixed focal length variations, (i.e. 24mm, 20mm, 16mm, 12mm, and 8mm and I believe it can be rotated to give intermediate values).

Best regards,
Tel

#31 Midnight Dan

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Posted 21 November 2012 - 09:35 AM

Hi Tony:

As others have said, a 5-6mm won't improve your views on most nights. While the scope is capable of 400x, the "seeing" conditions are what will limit your maximum magnification on most nights.

I find that on almost any night I observe, I can get to about 150x (13mm EP). On about half the nights, the seeing will allow me to get to around 250x (8mm EP). It's only on rare nights of perfect seeing, 2-3 nights a year, that I can use the scope's maximum of 400x and use my 5mm EP.

On those nights that I'm limited to 150x, Jupiter is a blurry ball with maybe some hints of cloud bands but no more. On the 250x nights I can see distinct bands and, depending on how good the seeing is, I can make out the great red spot if it's facing us. But details beyond that are hard to come by. When seeing gets better than that, then I can start making out finer details on the surface and in the cloud bands. And I can make out those details even with moderately powered eyepieces.

Point is, even if your scope is well cooled and properly collimated, you need to observe again and again to find those nights when you can see some detail on the surface. And you don't need a 5mm EP to see them.

As for shakiness, Tel has outline some ways to improve the stability. Another way is to invest in anti-vibration pads. I use them every time I observer and would not be without them. They seem expensive for what they are, but they reduce the vibrations by about 50%. http://tinyurl.com/cd7268d

-Dan

#32 Alex Post

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Posted 22 November 2012 - 01:11 PM

Congratulations on your new purchase !

#33 Tony from Tulsa

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Posted 23 November 2012 - 11:56 AM

UPDATE -THIS JUST IN!: After spending a few more nights getting familiar with not only the telescope, but observing in general, I have found that you guys are correct in citing seeing conditions as the main culprit. I've observed Jupiter and the moon extensively and have seen the "rippling" effect over both. Night before last, I could really see it looking at Jupiter. It looked like I was seeing a reflection on a pond sort of. Anyway, with that in mind I'm wondering if maybe a filter or two would help give my images some contrast? While I'd love to look through a Baader Hyperion 8mm X 24mm parfocal EP, its a little costly for me right now. Can someone explain a little further exactly how that EP works? Is it like an adjustable zoom lens? Also, I got my stuff together and got up at 4:00 AM this morning to set up and see Saturn for the very first time in my life. WOW! was it a rush! the higher it got into the morning sky, the brighter and clearer it was. That was a thrill. I can mark that off of my bucket list now! Again, thank you to all of you guys and gals for the warm welcome and awesome advice!

#34 Midnight Dan

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Posted 23 November 2012 - 01:02 PM

Hi Tony:

Yes, the Baader zoom is an adjustable focal length eyepiece. You can turn a ring on it and it zooms from 24mm to 8mm.

For contrast on planets, some people use the inexpensive sets of colored filters. They DO enhance the contrast a bit on certain features depending on which color you use. But they also impart a heavy color cast to the planets, which most people find off-putting. Those sets of colored filters tend to get purchased, played with for a while, and then put in a drawer.

As for bad seeing, it shows up in various forms. Sometimes it looks like rippling of the image, sometimes the image seems stationary but just out of focus. I've even seen it on some nights where it looks like a fast vibration. I though there was something wrong with my mount!

And yes, Saturn is one of the most amazing sights up there! You can find much better pictures of it anywhere on the internet, but there's nothing that compares to seeing it with your own eyes.

-Dan

#35 Peter9

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Posted 23 November 2012 - 01:33 PM

Hi Tony,

Although it can be purely atmospheric, the "rippling" effect can be caused by observing over roof-tops of houses etc. I suffer it when I observe to the East from my location. The cause is normally the heat escaping through the said roofs.
If it is the case, and if possible ,wait until Jupiter, or any other object, is clear of the roof-tops.

Celestron and Skywatcher both do 8mm X 24mm zoom lenses which are much cheaper than the Baader. I have one by A&E, which is the skywatcher under another name, and I am more than happy with the quality of the optics.

Keep at it Tony, your efforts will be rewarded. I have clear skies tonight, but for the second time this week, strong winds are preventing me from observing.

Regards. Peter.

#36 Skip

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Posted 26 November 2012 - 12:35 PM

Hi Tony,

Just like Dan, I bought a set of color filters to "enhance" the details on planets. Ha, used them a couple of times and they haven't been on the scope since. Probably my biggest waste of a few bucks.






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