Want to buy a telescope for 11 yr old grandson for under $100.?

Question

What is the difference between reflector, refractor, zoom? and what is altazimuth mount? does red-dot projection viewfinder help? what does a diagonal viewer do? will he actually be able to see the rings of Saturn, moons of Jupiter, the moon's craters?

Thanks to each of you for your informative answers. And thank you n2s.astronomy for the child's point of view.

Answer 1

Any telescope selling for under $100 is going to be a toy, not likely to show much. Here is a link to some starter scopes, but I'd really only recommend the first two on the page:
http://www.telescope.com/control/category/~category_id=starter_scopes

Reflectors use mirrors to form the image, refractors use a lens. Zoom eyepieces should be avoided. Mounts are either equatorial or altazimuth; the latter are much easier to use, and the only kind I recommend for beginners. All of the above scopes are on altazimuth mounts. Every telescope must have some kind of finder because their fields of view are so narrow. A red-dot finder is probably easier to use than an optical finder. Diagonals are only needed on refractors, when looking at objects overhead. Any of the scopes on that page will show Saturn's rings, Jupiter's moons, and the Moon's craters. They will also show bright star clusters, nebulae, and galaxies, once he learns his way around the constellations to find them.

Answer 2

A reflector uses a concave mirror to form the image. A refractor uses lenses. A zoom can be either but is usually a refractor.

An altazimuth mount is simply the name for a mount that can rotate on either the horizontal or vertical axis, with separate lock-downs for each of these.

The viewfinder is a low-powered refractor that assists in aligning the telescope. Some have crosshairs, others use the red-dot projection you mention.

A diagonal viewer changes the angle of the eyepiece to assist comfortable viewing.

It may be difficult to get a good 'scope for under $100, especially new. Buying used 'scopes is dodgy business that I'd recommend you avoid. Yes, a $100 scope should allow him to see lunar craters, and depending on light polution, the moons of Jupiter (which will appear as stars lined up with its equator), and Saturn's rings (but not well enough to resolve the Cassini Division, the gap between the A and B rings.) But if he has a serious interest in astronomy, I'd strongly recommend doubling or even quadrupling your budget if you can at all afford to do so. Kindling a child's interest in science is well worth the money.

My preference is for reflectors, by the way. The image tends to be sharper.

Answer 3

In my humble opinion, an 11 year old is old enough to have a real telescope, not a department store toy. [$100 department or discount store refractors are junk and not worth buying] Go to telescope.com and click on 'reflectors'.....look at the first two shown....both reflectors [SpaceProbe 3].....$99 and $129. One is on a altazimuth mount [up and down, side to side] the other is on an equitorial mount [aligned with the North pole]. Either one is a good starter scope. Small, but easily capable of showing Saturns rings, the moons of Jupiter, up close on craters of the moon.

If you have a few more $ to spend, get the 7th one pictured.....the Skyquest XT4.5, for $239. [these are often available used for about $150 or so]. It is also a reflector, and very easy to use......it is on an altazimuth mount known as a Dobsonian. Instead of a tripod, it sits in a sturdy wooden cradle. A sturdy mount is important. When you are magnifying a small image 100 or 200x, the tiniest motion is magnified in the eyepiece......can be very frustrating.

Hope this helps.....

In very basic terms, Refractors use a lens and reflectors use a mirror...... to gather light. Reflectors are generally less expensive for their size.

Answer 4

Hello inquiry -

A reflector uses a mirror to focus the image at an eyepiece near the "front " of the scope. A refractor uses lenses to focus the image at the rear of the scope - it's probably the more familiar - looking type. An altazimuth mount provides two degrees of freedom - one horizontal and one vertical. It's fairly easy to use , especially for a scope in this price range. Yes - a red-dot view finder will help him to locate and center the target before he looks for it in the eyepiece - much easier than trying to aim the scope by sighting down the barrel. A diagonal provides for easier viewing at the eyepiece of a refractor by reflecting it off to one side, so you don't have to crouch down to look up the eyepiece and through the tube. If you don't buy a toy, he will easily be able to see the rings of Saturn, 4 moons of Jupiter, craters on the moon, as well as many nebulae, star clusters, even a galaxy or two. Your price is too low. You cannot even buy a decent set of binoculars for $100. I would recommend that you consider the Orion Starblast. It can be found at oriontelescopes.com. It's a decent scope for the money, and he will not get totally frustrated with it, as he would with a $100 toy. The price of the Starblast is well under $200, and it's worth it.

Answer 5

Allow me to answer this from the kid's perspective. Many years ago when I was 10 or 11, someone gave me a telescope; a simple 60mm department store scope; and, I looked at the moon, then tried to locate other targets and failed miserably. I wasn't long before that scope was packed away never to be used again.

Many decades later, I again purchased the same exact 60mm scope. By then I had had many larger and better scopes, far more experience, and a good basic set of tools. I was surprised by just how well that little scope performed. I managed to see eight (ok "all of") of the planets, with very nice views of Jupiter, Saturn, Mars, and Venus; many of the brighter nova, clusters, and other objects. Better yet, the scope was such an easy thing to pick up and plop down, that it has since become one of my most frequently used scopes.

So yes, I believe that a simple $100 refractor would work well. They are slightly smaller, but far more resistant to abuse then a reflector; and an alt-azimuth mount (up-down, left-right) will do fine, as it is fast, cheap, and easier to use then an equitorial mount.

However, your grandson's degree of success will depend mostly on adult participation. He will need someone to help him locate targets and then to help him understand what he is seeing. Unless there is someone available to get him started, he will likely see what I first saw through my first scope; Just the moon, and a big black empty sky.

Answer 6

That is cool, but this might be more fun...

more bang for the buck, and a more satisfying learning experience as well.