What advantage does a reflecting telescope have over a refracting telescope?

Answer 1

For an amateur observer, the main advantages are price and size. A 12" reflector on a Dobsonian mount can weigh 80 pounds or so, have a 5 foot long tube, and cost maybe $800. A 12" refractor will be somewhere between 9 and 15 feel long, needs a massive mount, and could cost $100,000 or more. The color issues can be dealt with by the use of special, though expensive, optical materials.

For observatory telescopes, there is no contest. The largest practical refractor built was 40 inches in diameter. Larger pieces of optical glass probably can't be had, and even if they could, they would be impossible to support stably. A mirror can be supported all across the back, or even broken up into segments, so there is no limit to the possible size of a reflector. Solid mirrors up to 8.4 meters (330 inches) are now being produced, and segmented mirrors of 30 meters or more are being planned.

Answer 2

A brief summation of the above answers - larger mirror, more light gathering than refracting - bigger for less money - mirror supported so can be bigger - able to self grind -

I had a 100 dollar 60 mm refractor I used for many years, no color distortion ever.

Except for the curvature of the earth, the 200 inch at Palomar can see a candle on the sidewalks of London.

Answer 3

One advantage of a reflecting telescope is that it is much less expensive. A top of the line 4" reflector runs around$700, a top of the line 4" refractor runs several thousand dollars.

Answer 4

the advantage is the compactness of a reflecting the light back and forth between mirrors instead of refracting it inside a long tube. The clarity is better in refracting scopes but any good ones are too huge to carry around

Answer 5

One advantage is that you do not get distorted colors from a reflector the way you do from a less-than-expensive refractor - no purple rings around bright stars, for example.

A second advantage is that you can buy a larger aperture reflector than you can a refractor for the same money.

A third advantage is that you can grind the mirror of a reflector yourself and make your own telescope if you wish. It is impossible to grind decent refractor lenses unless you have special, expensive equipment.

Answer 6

The lens in a refracting telescope exhibits dispersion and absorption. A mirror has neither,

Answer 7

a reflector doesn't need as high a quality of glass to make the mirror, so its cheaper, plus you can make huge reflectors because the mirror can be supported form underneath, while refractors have nothing but the edges to hold the main lens up, this could result in lens distortion. mirrors do not chromatically disrupt light, so that the image is clearer, reflectors can be much shorter than a same size refractor

Answer 8

They are easier to make and thus cheaper per inch of aperture and more suitable for large apertures.

They are far lighter than refractors.

They don't suffer from chromatic aberration.