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ourobouros2k2
sage


Reged: 11/10/11

Loc: okc area, oklahoma
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tel]
      #5529580 - 11/20/12 08:27 AM

FWIW, When aligning, I always do a 2 star selecting stars at opposite ends of the sky. My alignments were always troublesome with solar system align with exception of when I used the mount for my old solar scope.

My guess is that when you changed eyepieces, the atmosphere couldn't handle the extra mag, blurring out the image. Seeing here in Oklahoma sucks most of the time, so you really cherish the good nights. If the image looked like you were viewing it through moving water, then it was a bad seeing night. You can view factors such as seeing and transparency (and other factors) on a clear sky chart. They look intimidating at first but are easy to catch on to. These really help when trying to determine if the atmosphere in your area will handle high magnification without much distortion.

http://cleardarksky.com/c/TulsaOKkey.html?1

explanation is posted beneath the chart so you will see that after a bit, it isn't that hard to read.


much luck,
Andy


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Tony from Tulsa
member


Reged: 09/30/12

Loc: Tulsa, Oklahoma
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: ourobouros2k2]
      #5529749 - 11/20/12 10:19 AM

Good advice guys. Thank you. Any thoughts on a Barlow? How much will it help with magnification and/or clarity?

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Tel
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Reged: 03/31/06

Loc: Wallingford England
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tony from Tulsa]
      #5530011 - 11/20/12 12:15 PM

Hi Tony,

I'm sure that not all others share my view, but I have mixed feelings about the use of Barlow lenses.

For pure observational purposes, I have several eyepieces covering the range I feel appropriate to the capabilities my Nexstar 8i, (the forerunner of the 8SE). These relate to focal lengths of 26mm, 21mm, 17mm, 15mm, 13mm and 10mm.

The 21mm, in particular, being a Baader Hyperion, is modular in its construction and thus can, with its forefront lens removed, be used as a 32mm.

EPs are however a personal choice so our colleagues here will have their own ideas as to what focal lengths suit them.

However, with this relatively extensive range of EPs, I feel little need to use a Barlow and in fact in avoiding the use of one, I do not introduce any more glass than necessary between eye and object.

On the other hand, astro-photography presents a totally different dimension where the use of Barlows is concerned, particularly when it comes to imaging the Moon or planets where very high magnifications may often be required but not at the expense of lesser light collection; the camera being a photon accumulating instrument, the eye, not.

As mentioned, this a purely personal view. Other opinions are bound to exist !

Best regards,
Tel


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Midnight Dan
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Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tel]
      #5530059 - 11/20/12 12:36 PM

I agree with Tel regarding barlows. I have a couple, but rarely use them on the 8SE.

They do have a uses in other areas though. As Tel points out, when imaging some of the smaller targets like the ring nebula, a barlow comes in handy for astrophotography. In faster scopes with shorter focal lengths, a normal range of eyepiece focal lengths can't get you to the highest mags that the scope supports so you need a barlow to help out.

But with a focal length of 2000mm, a normal range of eyepieces fro 36mm to about 5mm covers all the magnifications you could use in an 8SE. I prefer to use less glass in optical train so I'd rather have the eyepieces than the barlow. But on the other hand, for those starting an eyepiece collection, a low mag eyepiece plus a barlow can certainly be less expensive and will hold you over till you have the money for the higher mag EPs.

-Dan


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hopskipson
Pooh-Bah


Reged: 06/24/10

Loc: Queens, New Yawk, Light pollut...
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Midnight Dan]
      #5530530 - 11/20/12 04:06 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


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Tony from Tulsa
member


Reged: 09/30/12

Loc: Tulsa, Oklahoma
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: hopskipson]
      #5530676 - 11/20/12 05:33 PM

Quote:

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!


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Tel
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Reged: 03/31/06

Loc: Wallingford England
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tony from Tulsa]
      #5530750 - 11/20/12 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


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hopskipson
Pooh-Bah


Reged: 06/24/10

Loc: Queens, New Yawk, Light pollut...
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tony from Tulsa]
      #5530756 - 11/20/12 06:19 PM

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

James


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Peter9
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Reged: 10/30/08

Loc: Yorkshire - Born & Bred
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: hopskipson]
      #5531532 - 11/21/12 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.


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Tel
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Reged: 03/31/06

Loc: Wallingford England
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Peter9]
      #5531567 - 11/21/12 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

Edited by Tel (11/21/12 06:23 AM)


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Midnight Dan
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Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tel]
      #5531787 - 11/21/12 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


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Alex Post
Pooh-Bah


Reged: 09/24/08

Loc: Iowa, USA
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Midnight Dan]
      #5533942 - 11/22/12 01:11 PM

Congratulations on your new purchase !

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Tony from Tulsa
member


Reged: 09/30/12

Loc: Tulsa, Oklahoma
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Alex Post]
      #5535339 - 11/23/12 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!

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Midnight Dan
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Reged: 01/23/08

Loc: Hilton, NY, Yellow Zone (Bortl...
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tony from Tulsa]
      #5535465 - 11/23/12 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


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Peter9
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Reged: 10/30/08

Loc: Yorkshire - Born & Bred
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Midnight Dan]
      #5535526 - 11/23/12 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.


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Skip
Starlifter Driver
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Reged: 01/23/08

Loc: Fort Worth, Texas, USA
Re: Well, I did it! Bought the Nexstar 8SE. new [Re: Tony from Tulsa]
      #5540244 - 11/26/12 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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