best-at-(blank) telescope for $1,500?

Hi everyone,

I'm looking for a new telescope for $1,500 or less and I need help! Clearly, a good advice is to get an all-around telescope like an 8" cat. In fact, I was going to get the new celestron nexstar8i. However, after pondering the matter some more, I realized that eventually I would want something better and would have to retire the nexstar. Isn't there something I can get that I would never have to retire? Hmm, the implication is that I have to get a telescope that is best in the world at something, whatever that something is (not counting professional-grade telescopes, of course). Planetary views? Double-star splits? Wide-field vistas? Portability? Something. While an 8" cat is probably the ideal sweet spot of trade-offs, and is probably the ideal choice if you're only going to own a single telescope, I think what I would really like is to eventually have a collection of several best-at-something telescopes. So, is there such a telescope for less than $1,500 (new)? If not, what is the telescope that is the closest to being the best in the world at something, for less than $1,500? One further requirement -- goto or push-to is a must (mainly cause I like gadgets), and I don't care about telescopes that have the best-in-the-world go-to or push-to systems since I'll be using pocketSky anyway. And I'm not looking for a telescope that's best for solar or lunar observing.

Ok, clearly for DSOs, aperture is king (given a dark enough site) and things quickly go outside my budget. As for photography, you can easily spend 10K and still not be anywhere close to the best. How about wide field vistas? Well, I think really expensive eyepieces make a big difference there, and 2 of them for binocular views. Star-splits? I'm sure that in the near future, AO systems will become available to amateurs and those will be expensive as hell! What about planets? Hmm, the obvious answer is to get a 3-4" apo refractor. But, I think that a 5" apo is optimal in that respect, and that's out of my budget. (Any larger, and I think that to take advantage of the resolution afforded by the bigger aperture, the intermittent moments of exceptionally good seeing are a little too intermittent). But a 5-6" mak is within my budget, and I think it's pretty damn close to delivering the best amateur views of planets. What do people think? Also, it may be the best scope for portability. So looks like a 5-6" mak is what I want. Maybe a 7" if it has a good ergonomic case. Do people agree with this reasoning?

So, what about specific models? My requirement of go-to or push-to narrows down the list considerably. I'm mainly looking at the ETX125 w/UHTC vs. the Orion skyview pro 150 w/Intelliscope. That's a tough choice. Any suggestions? I'm leaning towards the Orion because of aperture, but the ETX has go-to instead of push-to, better coatings (or are they?), easier setup, and a hard carrying case. So, given the better coatings on the ETX, is the actual light throughput comparable to the Orion? Do people think a 6 inch aperture will give significant benefits in resolution, given the seeing? Is the extra resolution worth it? Is the orion mount better for photography than the ETX? Is having a hard case all that important, or is it overkill?

thanks

The best scope is the one you will use the most. A lot of folks stick with an 8" SCT for their entire observing careers, so it is a legitimate choice.

There are a lot of factors to consider that I don't know about you: where you live, where you are going to observe, if you need to load it into a vehicle, what kind of vehicle you have, your physical ability to lift a scope, how far you have to move it to get it to where you can use it, what kind of storage space you have, etc.

If those are not limiting factors to your using a scope, I would take a long hard look at the Orion XT12i. I have a 12.5" Dob and truly enjoy the views of everything from planets to DSO's from either the city or a dark sky site, and feel it will last a long time before I want to move up again (if I ever do). It moves around easily on a 2-wheel hand cart, and slides into the back of my SUV for transport to the dark sky sites.

Aperture rules. For about $1,000 you would get your push-to scope and have change left over for some accessories (which often end up costing much more than your initial investment in the scope).

Hugh Bartlett

Going to a public star party is an excellent suggestion. Most places I've lived have at least one such opportunity each month.

Get a pair of binoculars (and a star chart) if you don't already have these. Not huge ones, I'd go for 8x40 or 10x50. There's a pair of used Orion 10x50 Ultraviews advertised here for $80. Every amateur astronomer needs a good pair of binos.

For a first scope I actually lean toward something in the 8"-10" range. Of course, it needs to fit in your vehicle, and you have to be able to move it w/o getting a hernia! You'll be able to see and find a lot more with this size than you will with a 5" scope. Above 10" you really need to go to a truss scope, IMO, and that's over your budget.

In your price range, right here on Astromart I see an 8" portaball advertised at $1500. This does not have push-to, though, and it is not compatible with any push-to or goto system. It's supposed to be a really sweet scope, though. There's also a couple of LX200s, an 8" and a 10". Finally, if you can fit one in your vehicle, a 10" f/6 Discovery PDHQ is a possibility. A new one is about $1500 shipped, so you'll have to add a SkyCommander later (perfectly doable, though).

Have fun,

Duane

Hellow Rusian...

I think you have gotten some good suggestions. While $1500 will not buy the best planetary scope, the best portable scope, the best deep sky scope, it will buy you a very good scope that is capable of keeping you excited and observing for a long time to come.

THe best way to spend your $1500 requires not only hands on experience with telescopes but it also requires learning about what you really enjoy doing. Then you can choose the equipment the best suits your needs and budget.

As far as an ETX-125 or a Orion 150 MAK providing World Class Planetary viewing, as EX-ETX-125 Owner, I don't really think so. On an average night, set up the ETX-125 next to an average 10 inch Asian Dob and I think you would be surprised at the added detail the bigger scope would show. Certainly an 8 inch SCT is going to outperform a 5 or 6 inch commercial MAK.

So rather than trying to buy a scope that is best at something and not so hot at everything else, I think it is wiser to buy something that is pretty darn good at most everything and enjoy everything Astronomy offers.

This might be an 8 inch SCT or an 8/10 inch Newtonian on an EQ mount, 9/10/12 inch DOB... lots o choices here.

jon

Thanks for all the replies!

The consensus seems to be that aperture rules and that a large Dob or S-C is the way to go. I've been an avid amateur for over 5 years and been to tons of star parties and caught aperture fever as well. But, I'm also an optical engineer and recently started questioning some long-standing amateur beliefs (which is probably why I came off as a beginner to Jim, and why I started considering smaller instruments.) I would like to offer a few arguments against aperture fever, and I welcome comments.

1) Aperture gathers more light and lets you see dimmer objects, sure. However, no matter how large your aperture is, you cannot see an object whose surface brightness is less than skyglow. As you increase the aperture, at some point all that you're doing is making the background brighter. Where is this threshold, say, for suburban skies? I (for example) can only rarely make out the core in M33, so skyglow is roughly the surface brightness of M33 in my skies. The view does not get any better after 8" or so. I would even say that with fully dark-adapted eyes, a 6" gives a more pleasing darker background level.

2) Aperture gives you better resolution, yes. But, to take advantage of that higher resolution, one has to wait longer and longer for moments of better and better seeing (or use registax to do that!). Eventually the wait becomes too long. Where is the threshold? Well, it is a rare night indeed that a half-arcsecond double can be split, I think. A half an arcsecond is the theoretical resolution of an 8", so it would seem that's the resolution threshold (again, not counting image stacking in photography or sites with great seeing.)

3) Aperture limits the maximal field of view (visual, not photographic), independently of focal length or magnification. See Sky+Tel Oct. 2004, p. 127. The relationship is roughly FOV_max(degrees) = 12 / Aperture(inches). Higher FOVs are possible, but at the expense of light not making it into your eyeball, effectively reducing aperture. Thus, if you are a visual observer who likes to take in 2 degree swaths of the sky, then there would not be an improvement for anything above a 6" (admittedly 2 degrees is huuuuge.)

4) I'm an apartment dweller, fly a great deal, and nowhere near being permanently settled yet. Portability means more to me than to most other amateurs.

And, the 5th argument is what I was initially presenting in my first post:

5) I would probably like to get a serious telescope eventually, like a good big R-C. So, for right now, I would like an instrument that I would not have to retire once I get that monster. And I don't see myslef using the 8" S-C or a 12" dob if I have the R-C. I do see myslef using a portable instrument like the etx125 or the orion150 though. Seems to me that those are not far from being the best portable scopes. Right? Or, if there is another scope that's better at something than a top-of-the-line R-C, I'd like to consider those as well. I imagine a good apo is better at planets, but that's outside my budget for the moment.

So, am I making sense, or am I just not getting something?

I wouldn't hold my breath waiting for a true adaptive optics system at a reasonable price.

Dave Mitsky

Ruslan,

You ask an interesting question. Instead of buying a "Starter scope" and then moving up later, you are porposing buying your first "Keeper" scope. And then adding other Keeper's later.

From my experience and from what I have heard, once they have bought quality representatives of the following, they really never get rid of them:

a three or four inch apo on a portable (primarily) and solid (secondarily) equatorial mount,
a portable eight inch Dob

Therefore, if I had no scopes and did not want to step up through the years, I would probably buy the Dob and the refractor.

Alex

Hi Ruslan,

Well, I’m getting into this a bit late, but I’ll throw a hat in, what the heck. I would reinforce the opinions of most people here by also recommending an 8 or 10 inch dob in this case.

Anytime the inquiry is of the form “best all around visual performance available for $X”, where X is not a huge number, the answer is basically always a Newt.

Consider the versatility of such an instrument, say for example a 10” f/6. You can pop in an eyepiece with a field stop that maxes out a 2” focuser – a 40mm Pentax XL comes pretty close – and get 37.5 X with a roughly 1.7 degree TFOV for nice low mag sky sweeping. On the other hand, you have enough aperture to go to 300X planetary / lunar when the urge hits, and conditions cooperate, as well. That is, 300X with a tolerable 0.8mm exit pupil. As an experienced observer you know that when exit pupils get down to the 0.5mm range or less it makes for some observing discomfort. Many people have real difficulty tolerating such small exit pupils because of floaters and dimness.

SCT’s tend to have too large a central obstruction, not to mention spotty optics quality, to really provide nice high mag views. They are wholly unable to reach really wide true fields. I see your point about a 6” Mak – I’m in NJ also, our sky conditions here must be nearly the worst in the world, so there are a fair amount of nights where the aperture advantage of a 10” dob is at least partially nullified – but top quality Maks are still hard to squeeze into your budget with a decent mount, and are even more incapable of low mags / wide TFOV than the SCT’s. Finally, fast achromats are nice for wide fields, but can’t handle the high mags.

The only instruments IMHO that really match the versatility (and exceed the convenience) of medium sized dobs are 6” apochromatic refractors, and those of course are a notch above the $1500 realm. If you can spend the money I think a serious case can be made that the 6” apo is one of the best all around solutions but you’re talking about a lot of dough. (A fine 6” long focus achromat, like a D&G f/15 perhaps – but that makes a mess out of your portability concerns).

Yeah, a medium dob is not so small, but not so large and heavy either, and at least the mount is very simple and doesn’t add much bulk. You can go the DSC’s and poncet platform route, if desired, and still have a considerable portability advantage over a large GEM with counterweights and tripod. All that combined with the dob’s simplicity and ease of use will amount to a keeper scope, in all likelihood.

(Anyway, if you do retire it someday, what’s the difference? You’re an Astromart member!)

Nice job starting an interesting thread!

My $0.02,

Mike

I agree with some other recommendations here.

The Orion XT12i with object locator may be the way to go. Lots of bang for the buck. My view on portability is that if you get a 10" Dob only because of portability you'll have wished you had gotten the 12".

An alternative for the best bang for the buck is an entirely different tack. That's the Orion SkyView Pro 80ED GoTo Refractor. These also are very wonderful. If you don't believe this, check out the Yahoo Orion ED group and look at some of the pics there. This scope will enable you to get into some very serious astrophotography without breaking your wallet, although that will require a higher budget than you specified. At least you can get started, though. Orion also sells the 80ED on the more robust EQ-G GoTo mount for about $1,600US.

But if you just want to look, I'd recommend the XT12i and get some accessories, like some eyepieces, a Telrad, and a carry bag. Aperture is everything! You can always do things to make it easier to move.

Get a good used 6" or 7" Russian Mak-Cass or Mak-Newt such as a LOMO, Intes-Micro or whatever. Even a 7" Meade Mak-Cass would fill the bill. It would be near the best you could get for planetary, double star, and lunar viewing, as well as very good for brighter deep space objects. I can make out some galaxies fairly well in my 6" Russian Mak-Cass at a dark sky site. Gives better planetary views than my fast 8" Newtonian. I've become a lunar observer even though I once thought I wouldn't like it all that much because of my 6" LOMO Astele Mak-Cass. The OTA with 2" Mercury back and 2" Stellarvue dielectric diagonal was about $750 delivered. A TEC eyepiece turret set me back $500. A good Pelican Case was around $200 delivered. A Siebert BN22 binoviewer was $300. The LOMO Astele 150 Mak-Cass comes with a killer finder scope. You get 1/8 wave optics that give the best planetary and lunar views I ever saw. The Intes-Micro scopes sell for similar prices and can be had with 1/8 wave optics as well. You can get a good used mount in place of the TEC eyepiece turret for around $500 if you don't already have one.

An alternative is to get a good Synta EQ6 mount for under $1000 on the used market and mount a used long focus 8" Newtonian with high grade mirror and diagonal on it. No SCT will be able to touch it for high mag views.

Still, nothing can touch a good 6" Mak on a decent mount in the $1500 range if you like viewing fairly bright objects at high power. Achromats will have false color, Newtonians will have less portability and less ruggedness with higher maintenance requirements, and an APO refractor that can equal it will cost over twice as much.