Schmidt-Cassegrain Telescopes
Celestron has long been recognized as a leader in
Schmidt-Cassegrain technology. Our line of Schmidt-Cassegrain telescopes ranges
from the highly portable C5+ all the way up to the powerful CG-14, and includes
several cutting edge computerized telescopes. Celestron's potent combination of
superior optics, fine drive systems and well-crafted mechanics puts these
telescopes in a class by themselves.
Schmidt-Cassegrain, or catadioptric, telescopes use a
combination of mirrors and lenses to fold the optics and form an image. Incoming
light enters through a thin aspheric Schmidt correcting lens, then strikes the
spherical primary mirror and is reflected back up the tube. The light is then
intercepted by a small secondary mirror which reflects the light out an opening
in the rear of the instrument, where the image is formed at the eyepiece.
Some of the advantages
of the Schmidt-Cassegrain design are:
- Excellent optical systems delivering razor sharp
images over a wide field.
- High performance in almost all situations;
terrestrial viewing and photography; lunar, planetary and deep-sky observing;
astrophotography with fast film; CCD imaging.
- Best all-around, multifunction telescope design;
it combines all the optical advantages of both mirrors and lenses, while
canceling their disadvantages.
- Focal ratios generally in the range of f/10, which
is useful for all types of photography.
- A telescope that's compact, portable, easy to use,
durable, virtually maintenance free and has a closed tube.
- The best near focus capability of any type of
telescope design.
- Large apertures at quite reasonable prices.
- Many accessories available.
Schmidt-Cassegrain telescopes are designed to meet
many needs and these compact, portable, user-friendly telescopes have a strong
following. At Celestron, we pride ourselves on producing consistently superior
optics and earning our customer's devotion to the Schmidt-Cassegrain telescope.
Each optical system is individually hand figured and guaranteed to be
diffraction limited. Fine corrections are made on the secondary mirrors, that
smooths the optical figure. To maintain tight quality control, each Celestron
Schmidt-Cassegrain telescope is manufactured in the U.S.A.
Hand figuring of an optical system is a complex
optical procedure done only on a commercial basis by Celestron. The art of hand
figuring does take time but the results are easily evidenced by the superior
resultant astrophotographs and viewing obtained.
Celestron 's optical testing is performed on
double-pass auto-collimators in a temperature controlled environment. This
ensures the highest quality on a consistent basis. Our commitment to the most
careful optical fabrication and most stringent testing and quality control is
for one purpose: to produce the very best Schmidt-Cassegrain telescopes
available anywhere.
All Celestron Schmidt-Cassegrain telescopes utilize
the multicoated Starbright® coatings group. High Reflectivity (HR)
coatings are used on the mirrors for increased reflectivity and Anti-Reflection
(AR) coatings are used on the correcting lens for increased light transmission.
In fact, Celestron's Starbright coatings provide "the best light transmission by
a large margin over the competition," according to Sky & Telescope
magazine. In addition, the optical systems are optimally baffled to ensure the
highest contrast levels. To provide consistent customer satisfaction and high
performance, all Celestron Schmidt-Cassegrain optical assemblies, at each
aperture size, utilize the same superior optics, whether in a basic or full
featured model.
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