What is the difference between a refractor and a reflector telescope?
C B asked:
My son wants a telescope for Christmas, but we’re pretty uneducated as to which kind to get. He is 10, but extremely smart and interested. We don’t want a piece of junk, but yet we want something good enough to support his interest. Advice??
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My son wants a telescope for Christmas, but we’re pretty uneducated as to which kind to get. He is 10, but extremely smart and interested. We don’t want a piece of junk, but yet we want something good enough to support his interest. Advice??
February 1st, 2009 at 10:07 am
A refractor telescope uses a system of lenses for focusing the image on an eyepiece, whereas a reflector telescope reflects the image off spherical or parabolic mirrors to focus it on an eyepiece. Refractors get expensive quick; an 8-inch refractor probably would cost many thousands of dollars. An 8-inch reflector probably costs at most 2 thousand dollars. Get the telescope from a well-known dealer like Meade, Celestron, or Orion; avoid Wal-Mart. Expect to pay at least several hundred dollars for a good telescope.
February 4th, 2009 at 12:30 pm
As an Astronomer I see tons of different telescopes. The very best one you can buy is a dobsonian.
Here is one we recomend and people usually buy and are very happy with it ..
Reflector means it has a mirror in it ..the starlight comes in, bounces off 2 mirrors then hits your eyes. This is better than a refractor because the starlight is brighter and better to see it .
A refractor means the starlight comes in, travels through the tube right to your eye, resulting in a dimmer harder to see image.
The reason why we recomend the dobsonian is because it’s the best one because of the super long tube . It will bring in the best view and closer than any model ..we have tested 1200 different types and this one I gave the link for is the best . I have it myself. People who are wondering what to get are always happy with this one.
We let them bring them home to try out .
You can purchase it right off Orion Telescope site where the telescope is on. They have outstanding service.
When you do get one feel free to email me for ANY help at all.
February 7th, 2009 at 4:09 pm
Background: the most important characteristic of a telescope is its aperture (diameter). This determines the amount of light it can collect, which in turn determines how faint of objects you can see. It also determines how much magnification you can reasonably used. The maximum effective magnification is about 50 times the aperture in inches; magnifying beyond that results in fuzziness. (Apertures are often given in mm (25mm is approx 1 inch).)
For any given aperture, a good refractor will give better images than a reflector but at a much higher cost.
You can get a very satisfactory 6″ or 8″ reflector on a Dobsonian mount for a few hundred dollars. These telescopes provide great viewing and are portable and easy to use. (Portability is important, unless you want to spend $500 to take up space in your closet.)
Orion, Meade, and Celestron are the leading brands. I don’t keep up with year-to-year model changes.
Pick up a copy of “Sky & Telescope” magazine (it’s better than “Astronomy”) and look at the ads.
Contact your local astronomy club and tell them you’re looking for help in selecting a telescope. Amateurs are eager to help and to show off what they know. People will let you come look through theirs and you can see for yourself what you like.
I recommend Philip Harrington’s book “Star Ware”, which I think is now in its 3rd edition.
February 10th, 2009 at 12:39 am
A reflector telescope uses a concave mirror to collect light, whereas a refractor uses a biconvex lens for the same purpose.
At the amature level, a telescope that helps see the planets, satellites of big planets, lunar craters, sun spots (with filter), details of lunar/solar eclipses and bright stars should be good enough. Such a telescope may cost about $100-$150. A motor controlled telescope to steer to a given direction is very convenient, but may be a luxury for most of people to privately own it.
Your kid’s further interests can be fulfilled in a nearby Astronomy Club. Good luck.
February 13th, 2009 at 10:33 am
I’m a big fan of dobsonians (I’ve got 2) but they’re not that good for young children! They’re designed to be easy to move and kids tend to hang on to the ’scope and move it when it should be stationary. Not only that, but dobs are undriven, so they have to be moved by hand to follow the object you’re viewing- I’ve yet to meet a 10 year old who can do that. You can obviously get motorised mounts which will track the object for you (more expense!), but I’ve found another problem with youngsters - some of them look across the eyepiece rather than through it!
I’m passionate about teaching astronomy to children but I’d want to be very sure they could actually use and enjoy a ’scope before spending a lot of money on one.
But let’s assume that a telescope is the right thing for your son. Reflectors give you most bang for the buck, but the eyepiece will be quite high off the ground - maybe too high. Decent refractors are a lot more expensive, but the eyepiece is lower down, and when used with a star diagonal (which puts the eyepiece in a more comfortable position) are much more usable for short people. There’s a third type of ’scope, catadioptrics, which use both lenses and mirrors. There are some quite affordable ones, but I think the sub $500 ones are too small to give enjoyable views - there’s no “gosh wow”.
Whichever you choose, please remember that they take practice to use, and you’re never going to see things like the Hubble pictures!