Refractor is a light crop will mirror the system together. The world's first astronomical telescope is a Galilean refractor manufactured it for the use of convex lens. As the glass of different refractive index of light of different refractive telescope would have a serious difference, therefore, the subsequent use of compound refractive lens telescope as a lens, that is composed of two or more lenses to eliminate chromatic aberration (such as the United States Meade's ED series). According to the different optical path, Galileo refractor telescope and is divided into two Kepler telescope. The relative refraction telescope usually smaller caliber, that is, a long focal length, large-scale negative and thus higher resolution, more suitable to the astrometric do the work (such as measuring the location of stars, binary star angular distance, etc.).
Advantages:
Easy to use, manufacture simple.
Suitable for observing the moon, planets, binary star, especially for large aperture telescopes.
Compact structure, no additional maintenance costs.
Closed tube of air flow reduced the damage of image quality, while protecting the optical lens.
Easy handling, suitable for outdoor long-range observation.
War can be avoided imaging, high-contrast image quality.
Through achromatic design, can be very good to avoid the appearance of chromatic aberration.
Disadvantages:
Price than the Newton-type or high-style Green Card game.
The same caliber, the refracting telescope or more Newton-type card game Green heavier, longer and larger.
Due to restrictions on size, not suitable for observing deep space objects such as nebula and so on.
The shortcomings of coke is relatively small telescopes to refraction caused by the use of deep space objects appear filming more difficult.
In the achromatic design, from the color image will have a little more or less distortion.