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Discussion Starter #1 (Edited)
I just bought an Orion Skyquest XT8 and a few extra eyepieces which I'm expecting to arrive tomorrow. I'm already looking to broaden my selection of eyepiece choices with a 2" piece, but I can't decide on the focal length. Here's what's I've already got coming to me:

Telesope focal ratio: 1200mm
Aperture: 203mm
Focal ratio: f/5.9
1.25" eyepieces: 7.5mm, 10mm, 25mm

I also have a 2x barlow, so I have an array of magnifications including 48x, 96x, 120x, 160x, 240x and 320x.

I'm trying to decide between a 26mm and a 32mm (or even 38mm if it's worth it) 2" eyepiece. The options all herald a 70 degree field of view (compared to a 52 degree FOV for the 25mm eyepiece). I'll most likely use this particular eyepiece for "mowing the lawn" or just general wide field views of deep sky objects.

Currently I'm leaning toward the 32mm because I've already got a 25mm eyepiece. The reasons why I'm still considering the 26mm eyepiece stems from being able to get a wider field of view at a similar magnification. The 32 would let me get a nice, wide field for lower mag (38x) general viewing and I could zoom in with the 25 if necessary.

I dunno, what do you guys think? :zdunno:

I realize I should probably join an astronomy forum for this kind of stuff... but I admit I'll probably do that after the first few nights and I start looking for ways to get more out of my equipment.
 

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Raoul Duke
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I can't help you with your question due to the fact that I'm just not qualified enough. With that said, I can tell you that the greater the primary mirror, the greater quality you will have with your final visual. In most cases with land-based astronomy, a telescope's viewing space is the equivalent of looking at the sky through a coffee stirrer.

I bought a Bushnell reflector about nine years ago and I've used it ever since. It has a 3" primary with a 2.5x Barlow, but I may be wrong on those numbers. It's been a few years since I've looked at the specs.

I once held a digital camera up to the eyepiece (in macro mode) and took some highly detailed shots of the moon. This was without a mount and in the middle of winter, so you can believe that I had to discard 95% of the shots due to blurred edges.

There's nothing quite as humbling as seeing the rings of Saturn with your own eyes in real time. Nothing compares to it.

Enjoy it!
 

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Discussion Starter #3
There's nothing quite as humbling as seeing the rings of Saturn with your own eyes in real time. Nothing compares to it.
:)

I had a small 60mm refractor as a child, but I was so unexperienced and unfamiliar with the operation I wasn't able to get much out of it. Unfortunately those bad experiences with the telescope sort of killed my interest in the hobby, until recently. My interest was passive up until a month or so ago when I pulled out my fiancee's dad's Bushnell 60x440 refractor when her mom dragged me outside on a clear night to admire the stars. It only has an 8mm eyepiece so I'm stuck with 55x magnification, but that was enough to bring in Saturn and to see its rings. I suppose that got the fire kindled again, then after doing research online I came across the XT8 with an 8" mirror, mostly 5 star reviews across the board as an intermediate scope, for $350. I jumped on it last week when it went on sale.

I'm anxious like no other to get it tomorrow. With good seeing and away from the city, supposedly it can bring in a magnitude 14 star. :znanner: :znanner:
 

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Raoul Duke
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Right on. Get yourself a red-lense flashlight and a star-finder wheel. Make sure you get away from any city with dusk-to-dawn lights.

If you get somewhere dark enough and the skies are clear, you can actually watch satellites with the naked eye. You have to be patient, and you will likely see more than one meteor.

There's all kinds of stuff going on up there, but 99% of people never look up and wait. We're all too busy to not take it for granted, I guess.
 

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Minimum magnigication should not be less than 5 x the dia. of the primary
Maximum magnification should not exceed 25 x the dia. of the primary

hope that helps

Also Meade pretty well flooded the market with a free 26mm eyepiece with every scope they sold, you should be able to pick one up real cheap. check out cloudy nights http://www.cloudynights.com/classifieds/
 

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Discussion Starter #6
Yeah, I read the tip about magnification in my research. With a scope this size, atmospherics and light pollution are going to be my worst enemies from now on. I'm not sure how much usefulness I'll get from the 320x combination, honestly I think I'll be limited to the 240 or 160 on most [decent] nights. I might pick up a 17mm eyepiece to add 70 and 140 power to the mix.

I'm leaning more towards the 32mm; I'll get a better idea once I look through this thing for the first time tonight. I was getting some pretty nasty haze/blur at magnifications as low as 160x at a distance of only 1/4 mile or so this afternoon as I was alingning the finderscope. I'm hoping to get a decent look at Saturn before it starts setting before dusk, it looks like terrible seeing tonight though. :(
 

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Raoul Duke
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It's really amusing to focus in on a planet only to watch it slowly creep out of view. This would be the rotation of the earth.

Very humbling stuff.
 

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I've had telescopes since I was little (~1968); my first one was a cheap 4" reflector, and it's sitting on the shelf here. :)

25mm is a good size.

I'd buy one close to the upper end of magnification, and one lower, around 20x with a wide fov.

Your eyes will set the size optics you need:

Minimum and Maximum Useful Magnification

The pupil of a typical human eye has an opening about 5mm in diameter in subdued daylight. The pupil may contract to as little as 2.5 mm in bright light, and it may open to 8 mm when the eye is dark adapted. Magnifications smaller than values equal to the telescope's diameter in cm. will result in a bundle of light larger than the pupil, thus loosing image brightness. Magnifications larger than about 10 times the aperture in cm. will result in a bundle so small that the image quality will suffer. Example: The RHO 46 cm. scope can use magnifications between about 50x and 500x to good effect. Since the focal length is about 480 cm., thus means eyepieces of about 10 mm (480x) and 100 mm (48 x). Note that eyepieces are generally not available with focal lengths longer than about 50 mm (100x with the 46 cmm. telescope).​

Stolen from here:
http://www.astro.ufl.edu/~oliver/ast3722/lectures/Scope Optics/scopeoptics.htm

My current scope is a 4.5" swift catadioptric with an equatorial mount; I've been looking at bigger ones again... :rolleyes:

Suscribe to 'Sky and Telescope' or 'Astronomy' Magazine. Either are a great source of info.

A spot near (non ocean) water, with dark skies is optimal. The body of water acts as a thermal sink, and makes the air steadier.

"Seeing" is a term you should get familiar with; it comes and goes quickly. :)

Sometimes you can see Saturn's rings clearly, sometimes it looks like you're looking up thru a bowl of muddy water, lol. That's "seeing", as an observation quality.

BTW, telescopes do not help with meteor showers; they're long gone by the time you could watch them. Binoculars (almost never used) and a lawn chair works best for those.

Enjoy!
 

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Discussion Starter #9
Thanks for the tips Grog. I've got my upper limit eyepiece already, and so I feel more justified asking for the 32mm eyepiece now to fill the role of a lower limit lens. After trying to scan the sky with the 25mm eyepiece, I feel I could do with a lower magnification, wider field lens more than anything else at the moment.

I did get a few decent "teaser" peeks last night. Humid as can be and clouds rolling in all night, but I was able to get a few fuzzy glimpses of Saturn as it was setting under the incoming clouds :)mad:) at about 120x. I managed to see some vague color banding and the gaps between the rings on either side of the planet, but little else.

I was observing about 500 feet south of lake Erie; there was a bit of thermal distortion at those midrange magnifications but I felt my biggest problems laid in light pollution (the Ford plant to the SW, Lorain to the W, Cleveland to the E and various suburbs to the SE) and the terrible humidity/clouds that was present.

The moon I was able to look at in much greater detail; I started peering at it right as the sun was setting (clouds hadn't rolled in yet, much clearer sky) and was able to get a clear view at 320x. I swear, it looked like someone made a mess with plaster. :)

Otherwise, I poked around looking for a few of the Messiers, but with terrible seeing and all that light pollution, I couldn't see well enough to aim at even the brighter ones. I was able to see a LOT of stars I've never seen before (I'll guess in the neighborhood of mag. 9), so closely knit together it was like watching Star Trek. I've got to take this thing to a true dark sky site at some point, I feel its true capabilities straining to break through. :)

As far as the Perseids this year... I'm kind of bummed due to the whole full moon deal. Oh well, as we Clevelanders say, I'll "wait till next year."
 

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Unless you have a 'goto' mount, start with the easy stuff; the moon is awesome, but use a filter or you will go blind. :)

Planets are fairly easy, compared to the deep objects; for an 8" scope, there's usually a comet to see somewhere.

Tracking on most of the M objects is difficult, and takes good seeing; concentrate on what you can see, when you can see it. If the seeing goes bad, Jupiter or Saturn might still look ok.

You should be able to find all of the planets with an 8" scope. :) I've seen Neptune as a blue dot on a 24" telescope; Uranus and Pluto I've never seen. All the others are easy. :)

Orion is my favorite; it's bright enough that a lot of detail is visible; the closer planetary nebulae are nice when you can see them.

The mags I recommended include monthly star charts; that helps a lot, as do red flashlights.

The pirate thing with an eyepatch is also not a myth. :thumbsup:

If you know someone with a large farm in the middle of nowhere, talk them into letting you camp out sometime. Summer is better, with no fire necessary. :)

Any city boys I've ever met have been astounded when I throw a party at night. :)
Some of the guys from Germany had never really seen the milky way...

EDIT: Here's what you want for a lower power lens...
Unfortunately, its $450... and 2" diameter, which probably won't fit. But god, they look awesome. (drool)
http://www.televue.com/engine/TV3_page.asp?id=22&Tab=EP_EPO-41.0

:)
 

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Discussion Starter #11
Hmm, interesting. I was looking at these. The longest focal length in that series is 38mm. Do you think that would be a better addition to my eyepiece selection than the 32mm (also a 2" eyepiece)?

http://www.amazon.com/32mm-Orion-Wide-Field-Telescope-Eyepiece/dp/B000M89H72/ref=wl_it_dp_o?ie=UTF8&coliid=I2MH4KFFJPGIWI&colid=JGUKUWGC6FPM

I've noticed a lot of different configurations and designs when it comes to eypieces and optics. Any links to good reads?

I'm definitely starting out slow with what I look at, just wetting my whistle so to speak. My fiancee's grandmother lives on a farm about an hour south of here, it's a good deal away from most of the larger cities. I plan on heading down there on a good night to see what I can get. I also plan on going to what I've read is the darkest sky site in southern Ohio later this year.

Any opinion on solar filters? I've read just to skip them because they don't filter the UV stuff. And I do have this on my short list as well: http://www.amazon.com/Orion-Deluxe-Stargazers-Eyepiece-Filter/dp/B0000XMXWK/ref=wl_it_dp_o?ie=UTF8&coliid=IT74QFLG68Z1L&colid=JGUKUWGC6FPM
 

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I would read a bunch before buying more optics; that's not a bad lens, but as you'll only be buying one, I'd take my time. At least look at Meade and some of the others...

IMHO, Solar observing is dangerous, and you only get one component failure per eye. :(

Also, Do not use any solar filter that goes into the eyepiece; they can explode as they fail.

Lens configurations are varied, some better than others; you need to find which one fits your eyes and scope best. See if there's a local astronomy club; they're not always a$$holes. :)
 

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I personally wouldn't spend $400 for an eyepiece to be used in a $600 telescope. Spending that money on a larger scope or tracking would be a better use. I understand that your eyepiece set will stay with you when your telescope will change over the years (mine have), but I have also discovered over the years that what works good for one scope does not work as well on another.

There is a lot of information out there like the magazines listed above. Astronomy clubs are very helpful at getting you in contact with dealers, people, other clubs, and general information. Another advantage is you get to see a lot of different types of equipment.

If you want to learn more (especially when observing planets) check out ALPO Assoc of Lunar & Planetary Observers, http://alpo-astronomy.org/ They are very good at working with beginners and showing how to notice things you are missing. They have several training programs. Also consider using a refractor telescope instead of a reflector.

Also check out the Astronomy League for some observing list for deep sky, planets, lunar, binocular observing, city observing, asteroid.
 
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