Telescopes! - PeachParts Mercedes-Benz Forum

LandYaghtLover · #1 12-15-2010, 08:40 PM

I have been looking to get a telescope. Right now just browsing my options. I dont want anything too serious, yet I dont want anything that will make me want to upgrade a month later.

I found an Orion XT10 Reflector Telescope for just over $500 used. Has computer control interface.

But I know nothing of these. Cameras I know a little better. So I would normally assume a larger lens, such as the Orion's 10 inch, will capture more light than a smaller lensed telescope.

Anyone have a telescope?

dannym · #2 12-16-2010, 09:12 AM

I have one but it's not a very good one. Honestly I can see just as much with my binoculars. It's a reflector type. It has a large aperture but the focal length isn't that great.
I've been wanting a catadioptric telescope for a while but haven't gotten around to getting one. I would like a nice Schmidt-Cassegrain one day. Meade makes some really good ones.

The equatorial mount is kinda hard to figure out but once you get it, it's really nice to track object.

Danny

elchivito · #3 12-16-2010, 09:50 AM

A Dobsonian reflector telescope is generally considered to give the most bang for the buck, but I've always had trouble with seeing through them and there are two other issues that make them problematic for me. First, the optics are not enclosed and unless you're going to use the scope only indoors, in a dust and lint free environment all the time, (no pets) it'll require frequent cleaning. Also, they're heavy and large and not very portable.

I've had a Meade ETX 90 EC Maksutov-Cassegrain scope for about 8 years now and it's served very well as both a casual night scope and also as a terrestrial spotter with it's lowest magnification eyepiece. I like the Mak design because it's essentially a short, fat can that'll fit easily into a briefcase sized carrying case and can be used with a small portable tripod when necessary. I can take it hunting or camping with ease. It also has computerized tracking and a built in and upgradable star finder program that will "go-to" deep space objects. There are newer and larger versions of this scope now that have built in GPS and are much easier to use, but I don't use the computer features that often and it's always been adequate for me.
One thing you'll find yourself doing pretty soon if you find you're really into your scope is buying more eyepieces, and they can get pricey. I've got eyepieces that cost almost as much as the scope originally cost.
Orion makes nice scopes, and they tend to be less expensive than Meades. If I'm not mistaken the computerized xt10 retails for about 700 dollars, so 500 may or may not be a great price depending on extras you're getting with it and it's condition. Good luck!

pj67coll · #4 12-16-2010, 09:58 AM

I assume you are looking for a scope for astronomical purposes? In that case there are some rules of thumb you should be aware of.

Generally yes, the larger the prime optical surface the better. Usuallyl in Astronomy bigger is always better. Unless you are looking for very specialized instuments but if you are just looking for an uncomplicated scope to show you the objects in the night sky that is a rule that holds true.

The simplest and best bang for your buck will be a reflecting telescope on a Dobsonian mount. I have a small 4.5" one for Orion which is a good quality insturment optically and mechanically. It's disadvantage as with all dobsonians is it's lack of drive ability which means that it cannot track objects so as the earth rotates they zoom out of your field of view quite easily. Thus you have to move the scope continuously by hand.

This can be compensated for by buying an equatorial platform, which in fact is something I'm looking into right now myslef but it ads cost to the endeavour.

A telescope with a german equatorial mount with motor drives on the two axes or at least the RA axis will allow you to track objects once the mount is correctly set up and aligned but if you are buying such a scope, especially a used you must be sure that the motors work. Have this demonstrated to you at night tracking an object in the sky.

Generally the larger the mirror, the shorter the F Ratio which makes the quality of the optics of paramount importance as the shorter the F Ratio the more susceptible the image is to breaking down at higher power magnifications. Longer F ratios are not as subject to that problem but they typicaly have smaller fields of view than shorter F ratios and thus can be more suited to viewing objects like the moon and planets at higher magnification than wide field deep space objects such as start clusters, nebulae and galaxies which are usually viewed at lower power magnification in a much wider field of view.

Meade does make some good products, so does Orion.

A good Catadioptric telescope like a Celestron or Meade is a fine instrument but you need one on a german equatorial mount or with GOTO capability on an altazimuth mount and these mounts and electronic controls add to the cost of the scope at the cost of aperture.

With a scope the more you pay for in non-optical related stuff, such as the mount and computer control, the less you recieve in optics. Everyting's a trade off.

If you really are interested in getting a scope I'd urge you to look at Orion's cataloge and Meades as well. There are a multitude of good scopes available out there for decent prices. It really is a buyers market but you need to know what you want out of the scope and not have unrealistic expectations.

There's an old saying in the hobby. The best telescope is the one that get's used. It does you no good haveing spent 2000 plus dollars on a large scope that's too bulky to move around and set up and that consequently sits in a corner of the garage and is never used.

- Peter.

ILUVMILS · #5 12-16-2010, 12:29 PM

I would definitely spend the money on better optics, and forget about the GOTO scopes. IMHO, half the fun is finding targets which can't be seen with the naked eye. I've had a Celestron 102mm refractor for many years and wouldn't give it up for anything. It's not an ED APO, so it cost a lot less. I spent a few extra bucks on high quality eyepieces, and it was well worth it. I've never enjoyed using reflectors so I can't recommend them, but that's just a personal preference. I've also got a pair of Orion 80mm bino's which are great for casual observing. The objective lenses are treated with an anti-reflective coating to optimize them for night use. I paid about $500 for the scope, $300 for the bino's, and another several hundred for eyepieces. I've gotten many years of use out of all of them with no trouble whatsoever.

pj67coll · #6 12-16-2010, 12:51 PM

Looking at Orion and Meade's sites I see a huge release of new scopes that I'd not seen as recently as a year ago. Well worth looking at their sites and thining about the new stuff. I agree that there is nothing wrong with a good quality simple refractor. There's pro's and cons to all types of scopes.

- Peter.