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[Astronomy] Wanted: Thoughts on a telescope.


Robotengineer

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After getting some astronomy binoculars in February, I have gotten interested enough in astronomy to want to get a proper telescope, and have found one that looks to be good, a TAL-100RS, and wanted to see if anyone else here has had experience with it. I have read a couple of discussions/reviews and they seem to be quite positive. Have you had any experience with it, good or bad? Or could you recommend a different telescope that you've had a good experience with?

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My main concern is how much money you're spending for a 100mm refractor. I've been looking at similar scopes lately, and the one I think I'll be springing for is a 127mm reflector for $170. Do you know where the huge difference in price is coming from? My main metric is mm/$, and my most helpful resources were courtesy of our dear Dr. Plait:

http://www.slate.com/blogs/bad_astronomy/2014/12/01/telescopes_how_do_i_buy_a_telescope.html

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I agree, that Tal scope looks a bit overpriced. I have a Sky-Watcher 'Go-To' reflector bought some four years ago for half the price.

D=114mm F=500mm ~ it's a good telescope and the 'Go-To' is brilliant. I just plonk it out on the patio, it has been programmed with my Lat & Long and the time so all I do is line it up with two bright stars and it will then go to and track automatically any stellar object.

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It depends on what you want to do with it.

Refractors are excellent scopes optical-wize but are pricey.

Good if all you want to do is look at the moon and other not so distant objects.

Reflectors are cheaper by comparison and give more magnification in relation to their size.

Good for "deep sky" observation.

Me and my GF got a real kick from watching Saturn through our scope and not some picture!

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Thanks for the replies!

I was hoping to use it for looking at planets, the Moon, and maybe a couple of DSO's. The main reason I was considering the TAL is because everything I've read about it says it has much better optics than telescopes from other manufacturers that use Chinese/Asian manufactured optics, and less chromatic aberration. I too have some reservations about it, the price being number one and the fact that I can't get it from a recommended dealer. I do intend to attend a star party before buying anything.

@Reflector owners: have you seen good views of the Moon/planets with a reflector?

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Last month I spent a couple of hours looking at the moon and Jupiter, among others, with my 60's Criterion RV-6. The views were stunning! The best I have ever seen with that scope. Seeing conditions make a huge difference in viewing the planets, so I must have had perfect seeing that night. That old RV-6 is a 6-inch reflector and it still performs great.

Jupiter was brilliant, 2 big stripes were very clear across the middle, and the 4 Galilean moons were very bright. All that with a nearly full moon not very far away from Jupiter. The Moon was very good as well, I even snapped a bunch of pics using my phone held to the eyepiece.

Edited by Dartguy
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Guess I use an in-between-method then!

I use an astronomy app on the tablet to look for something interesting above the horizon.

Then I use the finder scope and finally through the scope itself.

The Moon captivates me the most though.

I don't know why. Perhaps it's because of the plethora of details to see.

And easy to find...

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  Robotengineer said:
I also wanted to add that I would rather not get a Go-To mount initially, because I would like to learn how to find objects manually. Go-To sounds like the HyperEdit of telescopes. :P

I tried the same thing. It gets fairly frustrating after a while if there's no one there to tell you how you're messing up and why you can't find something that your chart says is there and should be plainly visible.

You don't have to use the GoTo feature if you don't want to. And it's nice to have it if you decide you've had enough of trying Hard Mode. ;)

I'm with the others on the price; that seems high and they don't tell you anything that would let you know why it's that high. The only thing I can think of for that price point is if they're using fluoride optics or low-dispersion glass, but they don't say anything about it in the description. That sets off alarm bells - either the manufacturer is charging way too much, or the retailer doesn't know what they're doing or is also charging too much, or all of the above.

I've also never heard of Tal, but it may just be that they simply don't do much business in the US.

- - - Updated - - -

For the same price not that much more they have this.

I think that's what I'd go for if I were planning on spending that much. Or maybe one of the big Dobsonians, like this, or this.

Though it depends on what it is you want to focus on. Refractors are great for objects that are within the solar system - planets, the Moon, etc. However, for deep sky objects, like nebulae and other galaxies, having a big aperture is really helpful. The bigger your aperture, the more light you can gather, giving you access to fainter objects. Just depends on how much space you have to store it and how willing you are to haul around a big scope...

Edited by Sidereus
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  Sidereus said:
I tried the same thing. It gets fairly frustrating after a while if there's no one there to tell you how you're messing up and why you can't find something that your chart says is there and should be plainly visible.

You don't have to use the GoTo feature if you don't want to. And it's nice to have it if you decide you've had enough of trying Hard Mode. ;)

I'm with the others on the price; that seems high and they don't tell you anything that would let you know why it's that high. The only thing I can think of for that price point is if they're using fluoride optics or low-dispersion glass, but they don't say anything about it in the description. That sets off alarm bells - either the manufacturer is charging way too much, or the retailer doesn't know what they're doing or is also charging too much, or all of the above.

I've also never heard of Tal, but it may just be that they simply don't do much business in the US.

- - - Updated - - -

For the same price not that much more they have this.

I think that's what I'd go for if I were planning on spending that much. Or maybe one of the big Dobsonians, like this, or this.

Though it depends on what it is you want to focus on. Refractors are great for objects that are within the solar system - planets, the Moon, etc. However, for deep sky objects, like nebulae and other galaxies, having a big aperture is really helpful. The bigger your aperture, the more light you can gather, giving you access to fainter objects. Just depends on how much space you have to store it and how willing you are to haul around a big scope...

Thanks! I know it's not fluorite, as the fluorite ones that I have looked at are $2000+ just for the OTA :0.0:. Right now I'm thinking about getting a 6-8 inch Dob, to get access to DSO's as well as planets, and then if I enjoy planets more I could save up more money and get a nice refractor. I'm also going to attend a star party before I buy anything, just to have a chance to look through a couple different types scopes.

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How often are you likely to go to a dark-sky site, realistically? How large is your vehicle to get there? Where do you plan to store the scope? How easy will it be to get from storage to your back yard?

The scope you use because it is light, easy to transport, and can store somewhere close to the door is the one you'll get way more enjoyment out of. Unless you are in a real dark-sky site, the visual difference between a 6" and 8" isn't noticeable, but the weight can be. If you have a minivan/truck, and/or a dark sky site nearby, go for an 8 or 10". At those sizes truss tubes aren't really necessary IMO, and just add extra setup time.

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  moronwrocket said:
How often are you likely to go to a dark-sky site, realistically? How large is your vehicle to get there? Where do you plan to store the scope? How easy will it be to get from storage to your back yard?

The scope you use because it is light, easy to transport, and can store somewhere close to the door is the one you'll get way more enjoyment out of. Unless you are in a real dark-sky site, the visual difference between a 6" and 8" isn't noticeable, but the weight can be. If you have a minivan/truck, and/or a dark sky site nearby, go for an 8 or 10". At those sizes truss tubes aren't really necessary IMO, and just add extra setup time.

The trusses allow you to replace the "minivan/truck" with "anything bigger than a Smart Fortwo". ;)

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I cannot give you too much advice on telescopes as I am still on my 20x80's I bought a year ago. I find the wide field of view you get with bins much better for sky-scanning and learning your way around the various bit's and bobs, where as a telescope is much more complex to set up and aim (in general) and with a much narrower field of view so you really are going for a targeted spot in space.

If I was to give some advice though it would probably be as follows (regurgitated from pro's when I was looking):

Spend a lot of money on the mount/tripod, it's virtually as important at the actual scope, I would say more so but there's no point in having a lonesome mount.

Ignore magnification power - This is because you can put a “high power†eyepiece on basically any telescope and get a ridiculously high magnification power, but unless the telescope has a large enough aperture and quality optics to support that magnification, you won’t be able to get a sharp image. That “high power†eyepiece itself is probably also going to be very optically poor.

Optics - Get the absolute best that you can afford.

If you have the space a Dob will be an absolute light bucket for the money, biggest bang per buck as they say, but if you want to rely on computers and auto tracking etc, then look at a Schmidt-Cassegrain or Newtonian telescopes.

Check out this link for a nice summary: http://soggyastronomer.com/the-agony-of-buying-your-first-telescope/

Something else to have a look at is Skynet. I bought some time on their space telescopes in the Chilean Andes and around the world and had an absolute blast. Sure it's not getting all wrapped up and heading out to a dark sky sight, but it is very very rewarding, and when else would you be allowed to control a half meter Ritchey-Chrétien or a 20 meter radio telescope!?

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Whatever you choose it's going to be heaps of fun, and even if you end up trading up in the future it will not have been a mistake. Good luck!

SM

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There is a lot of good advice been given here. I agree that reflectors and catadioptrics (i.e. Meade, Celestron, etc.) have been better value than refractors for most astronomy interests for a long long time. Get a quality optics brand. The mount cannot be over-engineered! Unfortunately, off-the-shelf scopes never come with a sufficiently solid mount. That Dobo looks quite good actually.

Edited by Kaa253
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  • 3 weeks later...

After some more research and going to a star party/astronomy club, I'm leaning towards an Orion XT8 Dobsonian, it's well reviewed and satisfies my requirements observation. Does anyone else own one of these? If so, do you like it?

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As a matter of fact, I do have an XT8. It is nice for the sort of casual observation you seem to be going for. I have done a little photography with it, and it is not that great of course, without tracking et cetera, but it works. I have visually resolved some things of interest, easily all four large Jovian moons, as well as some bands, the Red Spot, crescent of Venus, Saturn (initially found by pointing at a bright but unidentified star. That was fun), lots of craters on the Moon (who would have guessed?) and the Orion Nebula, among other targets. I have not really looked at Mars, however, which strikes me as strange. I will have to remedy that.

Regarding aiming, the viewfinder is pretty good as relates to finding what you are looking for, iff you know where it is to begin with, and especially if you can actually see the target visually (or with binoculars). It is possible, but slow to point it without, and seems to me easier to align the viewfinder than some larger telescope viewfinders (with the obvious drawback of the 0 magnification one here).

Structurally, the base and telescope are sound. Granted, I have treated mine delicatley, but all the components are sturdy, and can hold up well after several years of bumping around. There is one exception, in my case at least, as one of the grips on the focus broke off fairly early on. This, however, poses no problem for overal useability and seems an anomoly.

As far as transportability, it is not as easy to pack and move as many smaller telescopes; it is bulky and somewhat massive to carry by hand for long stretches, but as a Dobsonian, it is very easy to set up once you get to a flat place, essentially just set the two parts together and lock some springs to hold the telescope to the mount. If you have a car/truck to move it with, you should be good, without need for any help.

Reading over some of your desired parameters, I would imagine that it would suite your needs pretty well, and I would gladly answer any specific questions you have about it.

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  • 2 weeks later...

Well, congratulations and godspeed! You really are in for an adventure.

I will try not to say too much, but I have to admit that I am quite spoiled: my grandfather made his own telescope back in the heyday of garage amateur astronomy; a 12.5" (~320mm) Newtonian reflector with a correction motor added later. It is now mine, and I have not used it much in the last 10 years. When building your own, learn a lesson from the Hubble; the specifications for the primary mirror are of critical importance. Be sure your intended focal length and concavity are compatible with an existing line of eyepieces, or you may need those to be custom-made as well. The primary mirror should either be special-ordered or fabricated professionally, just like a major observatory; glass grinding, polishing, and coating is by no means a DIY project anymore. Also, it would be in your interest to subscribe to a periodical for amateur observers; if you are just interested in skywatching, I'd recommend Sky & Telescope ; their focus has always been on observing the night sky. If you can't or don't want to have it delivered to you, you can always subscribe to the website too, although I believe the online content is more limited.

Again, best of luck.

Edited by Hunting.Targ
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