Telescope?

Question

How powerful would a telescope have to be to do me any good? In terms of getting a cheaper one to just get started. Any info would be appreciated .

Answer 1

The best telescopes can magnify, under ideal conditions, about 50X per inch of aperture and still be useful. Under normal conditions, expect the image to break down after 30X per inch. In other words, a 4.5 inch reflector (if the optics are decent) can give about 135X magnification under normal conditions, and an 8 inch scope can give about 240X. Your mileage may vary. Stay away from cheap department store scopes...they might give you 10X per inch, beyond that, they are junk. The most important part of the telescope is the mount that the scope sits on. If it's wobbly, it will be of no use to you.

If you are just getting started, a good pair of 7X50 binoculars might do the trick, to get you familiar with the sky and some of the brighter objects in it. The kind of telescope that gives you the best bang for your buck is a Newtonian reflector on a Dobsonian mount...these are available from Meade, Celestron and others, but my favorite Dobs are from Orion Telescope. The mirrors have to be periodically aligned (collimated). These scopes are excellent for deep sky objects like galaxies, open and globular clusters and nebulae, because they have good, wide aperture.

If you want a smaller scope, a good refractor will set you back about $500, plus a little more for a decent mount. I have a small refractor on a sturdy mount, the whole kit cost me over $1600. You don't have to go that crazy.

Stay away from scopes that use 0.925" eyepieces. Go with 1.25' eyepieces. Most department store scopes ship with some of the worst eyepieces imaginable. Expect to spend for a decent set of eyepieces. Plossls are a good way to start out. You can spend upwards of $600 JUST for a single eyepiece (Televue Naglers, for example).

A good scope for you to start out with would be the Orion 4.5 inch Dobsonian. It runs $200 plus shipping, and includes two eyepieces. It's the starter scope I always recommend. I got the Starblast, which is the same scope, just shorter, for my niece, because she isn't tall enough yet to use the full-sized scope. When she gets old enough, I will give her my 5-inch Schidt-Cassegrain scope.

One thing to remember...the higher the magnification, the dimmer the object. Planets are good from 80X to 200X. Beyond that, atmospheric turbulence makes further magnification ridiculous. Double stars are good at 120X on up. Galaxies and nebulae are actually quite large, so viewing them at 10X to 40X is pretty much all you want, unless you have a HUGE aperture (like 10-16 inches). Beyond that, the already dim object will become unseeable. A few bright nebulae (like the Ring Nebula in Lyra) can withstand more magnification. If a place sells its scope by touting its amazing magnification, steer clear.

Hope this helps!

Answer 2

Power is the least important aspect of a telescope. What you should look for is aperture. Aperture means the diameter of the primary mirror or lens of the telescope. The larger the aperture of the telescope, the more light it can collect.

This is important because distant objects are very dim. Once your telescope collects enough light to see them, then it typically takes a fairly low powered eyepeice to magnify it sufficiently.

You can find a good used telescope for $150. A Celestron 4.5" Newtonian on an equatorial mount will get you a good view of the planets, star clusters, nebula, and some deep space objects under dark skies. You will be able to see the rings around Saturn and just barely make out the bands on Jupiter. At times you may be able to see the icecaps on Mars with it. It can also easily be outfitted for astrophotography, which will allow you to see more (cameras see more than the eye). The same telescope new would run about $300-$399. You may be able to get a used 6" for that price.

If you want to spend about $400 you may be able to find an 8" Celestron or Meade Schmidt Cassgrain.

Dobsonians are the cheapest and you can get a used decent sized one (8 to 10 inches) used Orion for $300, maybe less.

If you don't want to spend as much as $150 then I recommend good binoculars. I can see the Moons around Jupiter with my 7x50 multi-coated Simmons, and some nice star clusters and the Milkyway.

You can find used telescopes in the classifieds at www.astromart.com or www.cloudynights.com
You can find some good deals for new and used on eBay sometimes.

Don't buy anything from a department store and I'd steer clear of Tasco and Bushnell. Don't buy anything that emphasizes power. I rarely use any eyepiece more powerful than a 25mm or 25mm with a 2x barlow.

Be sure to research before you buy as different telescopes are better suited to different needs. Dobsonians are good for deep space live observing but are difficult and costly to outfit for astrophotography. They're also bulky. Schmidt Cassgerains are compact and most can easily be outfitted for astrophotography if they're not astrophotography ready, but they have to use a corrector plate which slightly reduces the amount of light they collect (not a problem if used for astrophotography!). Telescopes also come with various bells and whistles. If you want something that isn't much hassle then you may want to go for something with a goto system that finds objects for you, or a navigation system that directs you where to point it. This all costs money though and you may have to make trade offs.

Answer 3

Beginner's Advice

1) Binoculars, even cheap ones, are sometimes a good substitute for a cheap telescope. In addition, binoculars are almost always good companions to a telescope.

2) Avoid department store, toy store, and "Nature/Science" store telescopes. I cannot restate this strongly enough: STAY AWAY from department store telescopes!

3) The primary purpose of a telescope is to gather light. Thus, all other things being equal, beginners should buy the largest aperture telescope they can afford. A 6" Dobsonian reflector is an excellent first telescope.

4) BUT, if the instrument is too large, you may never use it. Be realistic about what you're willing to lug around.

5) You don't need more than 3 or 4 carefully chosen eyepieces in your collection at first. The minimum quality you should consider are Kellners (and their offshoots). A barlow is useful tool for doubling your collection at minimal cost.

Answer 4

When you say "powerful", I'm assuming you're talking about the magnification, or power. That depends on what you want to look at. If the moon interests you, you need 50 to 100X. At 50X, the moon nearly fills up the entire eyepiece when you look through it. 100X will show you more detail. If you want to look at planets, 200X-300X is sufficient. You'll be able to see the rings of Saturn, or the moons of Jupiter or Saturn. If you want to look at a nebula (a gas cloud left when a star went Nova/Super Nova and exploded), you'll only need 15 to 20X. The Orion Nebula is large, and you need to reduce magnification down to around 20X. Looking at a plain old ordinary star, it doesn't matter what power you use, it will still be a point of light. Some stars are fascinating. An example is Albirio in the Cygnus the Swan constellation. It is actually 2 stars orbiting each other. One is yellow, and the other is blue. The yellow one has a surface temperature of 3000-4000 degrees F. The blue one has a surface temp of about 10,000F. Hence the colors. in this case, about 200X wil show you plenty of detail. There's other things to look at, clusters, variables, doubles, etc. You can see plenty of detail with magnifications I've already discussed.

If you're considering buying a scope, let me recommend this: save your money and look for an astronomy club or association in your area. I live in San Jose, CA, and the name of our club is the San Jose Astronomy Association. Do a Y! search. You don't need to type in the whole thing. Just use sjaa. You will discover that membership is only $15/year. They also offer another plan for a little over $50/yr. That includes membership and a one year subscription to Sky and Telescope magazine. One of the benefits of being a member is you can check out scopes and equipment for free! For up to months! That is what your membership fee goes to, at least most of it. They buy equipment with the money, and explains why you don't have to pay a fee to check things out, Going to meetings or star parties, you will learn answers to all the questions you now have. And all the members are more than happy to help you with your questions. After you've been a member for a while, you will then have experience with various types of scopes and equipment. Now you can make a much better decision on which scope and equipment to buy (reflector, cassegrain, or refractor? Plossl, Nagler, or lanthanum eyepiece? etc)

Good luck!

Answer 5

I will suggest that you visit these two excellent sites on telescopes...you will come to know which telescope suits you best...

Answer 6

These 2 links might give you valuable info on buying the right telescope:
http://www.scopereviews.com/begin.html
http://findascope.com/

Enjoy gazing at the stars !!!