Author Topic: Considering 2 (used) reflectors for 1st scope  (Read 1192 times)

postbypopect

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Considering 2 (used) reflectors for 1st scope
« on: December 26, 2017, 09:22:27 AM »
Hello all, I'm considering two utilized scopes for my very first, both are for sale locally for the same asking price ($200).  I'd prefer to stay within this price range as I am uncertain how much time I'll be spending  and I don't want to drop $600 on a scope that ends up being used half a dozen nights per year.  Portability is important, I'd like to have the ability to put it in my car and take it when I go camping but I believe either one is good for this.  My principal interest is watching deep sky objects but I'll obviously spend time seeing the planets and moon.

Both I'm considering are:

Sky-Watcher 6" dobsonian

or

Orion Skyview 6EQ

Ideas?



pensranbafarc

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #1 on: December 28, 2017, 01:26:04 AM »
The 6EQ might be a better value but I'd recommend the dob if its optics are good. Why? The ease of use of a dob wins the day, that's why they are so common now.

Gregory Station

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #2 on: December 29, 2017, 12:58:49 AM »
Both are good scopes. The SkyWatcher Dob will be easier to use and transport. Do you have any experience with EQ mounts? They can be more trouble than they are worth in beginner scopes. I have a computerized EQ and a manual Alt-Az and the Alt-Az gets used 4x as often.

ticploodunghen

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #3 on: December 30, 2017, 02:35:23 PM »
I have no experience using either type of mount. When I was very young my father showed me some views of the moon and a couple planets with his refractor (20+ years ago). I tried using a very low quality scope out in NM while on vacation with family a few years back but don't remember seeinganything - thought it was as easy as pointing it into the sky and looking through the viewer, didn't bother to read the user manual or even check it out inside before taking it out into the dark. Naked eye viewing was more enjoyable.

I recently took a trip to an observatory of some note and also attended their star party. I was treated to views of jupiter/saturn/mars as well as m33, m31, m57 and a couple other M objects whose designations I forget through some very nice telescopes of all sorts. This sparked my interest.

I'm not intimidated by the idea of the EQ mount but perhaps that is due to my lack of experience in setting them up and locating objects.

Edit to add: Initially I was set on and am still leaning towards the EQ mounted reflector (partially because on first look the seem easier to transport with their shorter tubes but they do require more set up time) but decided I should at least look at the dobs as well. Are both of these scopes capable of producing the same image quality assuming equivalent eyepieces are used with the same atmospheric conditions?

vuicapathvie

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #4 on: December 31, 2017, 03:41:24 PM »
I think it is a real toss up.
I think I would prefer the dob because of a longer focal length; easier to collimate, easier to find a good focus at high power....
but that is Me ( I spend Far more time on the planets/moon). F/5 used to be ? 'suspicious', 'dumpy', but the quality on a LOT of the faster mirrors these days is Much better !!
If you are at all handy with some hand tools, and since you are mainly interested in deep sky (so, wider field of views?) I would suggest getting the f/5 with the equatorial. The equatorial mount might be very useful in time. You can get used to it whenever you want. When you get the scope, build a dob mount for it, or a simple alt az plumbing pipe mount you can easily break down and transport. You'd have the best of both worlds.
High power might be a bit harder to get to with the shorter focal length, but there are ways to get there.

precaregmo

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #5 on: January 03, 2018, 10:18:33 AM »
I would go for the Sky-Watcher 6 inch dob.

Why? I am a little suspicious about the quality of the tripod and the mount of the Orion Skyview 6EQ.

I have the Celestron 150 XLT Omin on a CG4 with the 1.75 inch tripod. Very reliable and steady combination. The Orion mount and tripod in the advertisement does not appear of the same quality. Mind you, I have not seen or used this mount and tripod I only surmise this conclusion from the picture.

L.

grounincalpay

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #6 on: January 03, 2018, 07:17:35 PM »
Good points already made. The only thing I'd add is that Orion is notorious for not helping non-original owners with any parts/mechanical issues with their scopes if something is missing or damaged. Personally I avoid used Orion scopes because of that. I believe Sky-Watcher is better on that front so that's the option I'd choose.

Cheers,

Pauly

slotiniphin

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #7 on: January 04, 2018, 03:53:16 PM »
Hi I love my 6" f/5. I love the EQ mount. Once you set your latitude, all you have to do each time is plunk down the scope
with the axis pointing north and make sure it is level. What this buys you over the dob is that one twist of the slow motion
dial keeps the image centered. This is helpful when using high magnification because with the dob you will have to keep
nudging the scope, and sometimes a controlled nudge is hard with a standard dob base.

BoldAxis is correct, the celestron version of the CG4, has a much better tripod. I have both tripods, the celestron is a beast and heavy but it is solid. The orion is kind of spindly but it will work with this scope. You will experience some vibration when you have to focus or if it is windy.

The 6" EQ will have a wider field of view and will require a little more love as far as adjustment.
The 6" dob is the opposite, a little narrower field of view and little less adjustment.
The 6" dob mount will be sturdier than the EQ and will settle down faster in wind or when the scope is touched.
The 6" dob will be easier on your eyepieces.

I think both of your choices are good ones. $200 seems a little high for a 6" used dob.
It also depends upon accessories that are bundled with it. Are there reasonable eyepieces,
a finder. If your budget is $200, I don't want you have to spend another $100 or more for
eyepieces and a finder.

Tawakal Stahlberg

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #8 on: January 04, 2018, 08:13:58 PM »
Thanks for the replies so far guys. Sounds like I might as well flip a coin.

Neither scope comes with any extras beyond what they ship with; the dob is (according to the owner) assembled but never used, so it may make the Orion a "better value" if you consider value a percentage of the original purchase price.

Quality of the mount/base/tripod is certainly a concern, I imagine a shaky image would be very frustrating. If there were a good condition used Omni XLT 150 around me that would seem to be the obvious choice with it's much more substantial tripod but no dice. I'm just simply not going to spring 2.5x my self imposed budget buying a new scope that I may end up barely using. The way I look at it is if I spend $200 on a halfway decent used first scope and actually end up using it enough to justify buying something better I can just donate this one to the local astro club without losing much $ and then spring for a ~$1k telescope.

Santosh Wolf

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #9 on: January 09, 2018, 12:59:50 AM »
Yeah seems everyone on Craigslist buys stuff yet gets bored 5 minutes after setting up lol

dont believe it, but unless they dropped it it should be fine. Inspect the mirrors. Look down the tube to inspect the large primary mirror. Remove any eyepieces to inspect the smaller secondary.

As as a first scope I'd grab the 6" dob. I wouldn't mind owning one myself.

laycacdownsell

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #10 on: January 10, 2018, 07:02:40 PM »
If your general interest is dso, then the 150mm/f5 should be sufficient for your needs. I would not worry about the mount, should be eq3/cg4. Set your latitude and point it north, use a good compass if desired.

Good viewing,

Dave

John Sanchez

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #11 on: January 11, 2018, 08:36:58 AM »
The 6" dob is an easy choice. Go for it!

James Clayton

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #12 on: January 11, 2018, 11:04:47 AM »
The primary mirror-cell on a Sky-Watcher 6" f/8 Dobsonian is not quite up to snuff, as seen in Fig.i...

http://i.stack.imgur.com/8Ju4o.png

It employs a rubber grommet of some sort, which will degrade over time, and instead of a metal spring for the adjustment screws. Perhaps no big deal for an f/8 that one might not collimate that often. It may be possible to replace the grommets with springs in future.

The all-metal cell of the Orion 6" f/5 has metal springs for its adjustment screws: fully adjustable and fully collimatable...
The focusser is very important, as it is the most mechanical part of the telescope, and the one on the Sky-Watcher 6" f/8 may be superior, and does allow for the use of 2" oculars with their wider fields-of-view...

http://www.opticalvi...s/large/225.jpg

The tube-rings on the Orion 6" f/5 allows for rotating the tube for a more comfortable focusser and eye position. Focussers on Dobsonians are in a fixed position; forever.

A 6" f/5 is more versatile in observing the gamut, everything, and from a low 23x to over 200x with 2x and 3x barlows; however, only 1.25" oculars are possible.

I have the same Orion 6" f/5, and with its tube-rings and dovetail interface, I enjoy the versatility of placing it on either an alt-azimuth or equatorial...
The equatorial can be motorised, for automatic hands-free tracking of any object...

http://www.telescope...ts?ensembleId=6




notaslasof

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #13 on: January 12, 2018, 10:34:36 AM »
Quote
Quote
The focuser is very important, as it is the most mechanical part of the telescope, and the one on the Sky-Watcher 6" f/8 may be superior, and does allow for the use of 2" oculars with their wider fields-of-view...
Moreover, f/8 is much more forgiving than f/5 as far as the focuser is concerned. To focus at high power in an f/5 scope, you really need a high-quality Crayford focuser, preferably with dual speeds.
The two-inch focuser is really a big deal. The only downsides of f/8 are the longer tube and the narrow field of view. But an f/8 scope with a 2-inch focuser has a wider field of view than an f/5 scope with a 1.25-inch focuser.

<p class="citation">Quote
The tube-rings on the Orion 6" f/5 allows for rotating the tube for a more comfortable focuser and eye position. Focusers on Dobsonians are in a fixed position; forever.
True. But the eyepiece angle on a well-designed Dob is pretty much optimal to start with, so there's no incentive to rotate it. Rotating is only a really big issue when using an equatorial mount.

<p class="citation">Quote
A 6" f/5 is more versatile in observing the gamut ...
[/quote]
Not if the f/8 has a 2-inch focuser and the f/5 has a 1.25-inch focuser. That evens the score.

<p class="citation">Quote
I have the same Orion 6" f/5, and with its tube-rings and dovetail interface, I enjoy the versatility of placing it on either an alt-azimuth or equatorial...
[/quote]
That's certainly a nice option -- but it comes at the price of purchasing two mounts.

The Dob would certainly be more stable than the 6-inch f/5 on an AstroView mount, but both should be just fine. The AstroView is a little underbuilt, but it should be adequate for a 6-inch f/5 tube.

The learning curve for a Dob is zero -- most beginners at star parties can use one without instruction. It does take a little while to get used to the quirks of a German equatorial mount, especially in combination with a Newtonian, which presents several gotchas. But most people can master them after 10 or 20 hours of use. And once mastered, they are very, very nice for tracking objects at high power, even without a motor. They also offer more options as far as star-hopping is concerned.

Pat Young

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Re: Considering 2 (used) reflectors for 1st scope
« Reply #14 on: January 12, 2018, 12:13:30 PM »
The Dob will be easier and quicker but the eq can be better for finding objects and can be motorized easily for tracking.I'd be very tempted to get BOTH.