Refractor telescopes (also known as
dioptrics) are probably what most of us think of when we hear the word
"telescope." Refractors have a long, thin tube in which light passes in a
straight line from the front objective lens directly to the eyepiece, at the
opposite end of the tube.
Refractor telescopes have many advantages,
- Simplicity of design, which translates into
reliability and ease of use.
- Little or no maintenance requirements.
- Excellent lunar, planetary and binary star
- High contrast images with no secondary mirror or
- Sealed optical tube, to protect the optics and
reduce air currents, which tend to degrade image quality.
- Permanently mounted and aligned objective lens.
The 60mm (2.4") refractor is the most popular
telescope size for beginning astronomy enthusiasts and for casual gift-giving.
This size telescope is perfect for introducing newcomers to astronomy, at an
For astronomical observing, the 60mm refractor allows
you to see lunar details, Saturn and its rings, Jupiter and its moons, the
phases of Venus, larger globular clusters, bright double stars and some bright
nebulae. After adding an optional solar filter, you can observe activity on the
sun. In addition, a 60mm telescope can be used for terrestrial viewing, bringing
the world closer to you and allowing you to observe wildlife, distant views and
The 70mm models serve the beginner to intermediate
observer who wants
slightly more aperture than the 60mm models and allows you
to see more detail on objects
Celestron's 80mm and 102mm refractor models are top
choices for beginning observers who want to start with a more powerful telescope
and for intermediate level astronomers. These instruments perform equally well
for viewing within our solar system and for deep-sky observing. Starting with a
more powerful telescope can be a good option when you're looking for an
instrument to grow with as you explore the hobby of astronomy.
Celestron offers two different options in refractor
telescopes: the altazimuth mount and the equatorial mount. The economical
altazimuth is the simplest type of mount, offering two motions: altitude (up and
down) and azimuth (side-to-side), for an easily achieved full range of motion.
Celestron's equatorial models use the German equatorial mount with setting
circles and slow motion controls on both the right ascension (R.A.) and
declination (DEC.) axes. These features make it easier to locate and track
While observing, you'll notice that as the earth
rotates on its axis, stationary stars appear to move across the sky. Thus, due
to the earth's rotation, the object you're viewing will float out of view in
both axes, over time. A telescope on an equatorial mount can be aimed at a
celestial object and guided with the slow motion controls to follow the object
across the sky and keep it in the field of view of your telescope.