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RC : Ritchey-Chretien Astrographs
Astrography Telescopes by GSO
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The World's Finiest Astrophotography Telescopes with unmatched optical precision - MADE IN TAIWAN
India's Best Telescopes for Deep Space Astro-Photography.


Special features of the newest RC-6" to RC-16" Astrographs
  • Ideal for astrophotography - due to virtually coma-free imaging!
  • True Ritchey-Chretien Cassegrain-type optics produce super flat field!
  • Flatter image compared to SCT and aplanatic/corrected SCT designs
  • Hyperbolic quartz primary and secondary mirrors with 99% reflectivity dielectric coatings for carbon fibre RC 8", RC 10" and RC 12" models   
  • Carbon-fibre optical tubes have outstanding thermal stability
  • Hyperbolic quartz primary and secondary mirrors with 96% reflectivity enhanced aluminium coatings for metal tube RC 10" & RC 12"   
  • Crayford style large 2" 10:1 microfocuser on RC 8" astrographs
  • Crayford style LINEAR 3" 10:1 microfocuser on RC10"/12" astrographs
  • Laser etched focuser drawtube setting scale 
  • RC 6" has a metal tube, BK7 mirrors (not quartz), Crayford style 2" microfocuser, 40mm of microfocuser drawtube travel (not 50mm) and 
    a Skywatcher/Vixen style full-length (32cm) dovetail bar
  • RC 8", 10" & 12" have long 50mm drawtube travel (not 40mm)
  • RC 10" and RC 12" models have upgraded/smoother/stronger stainless steel reinforced Crayford 3" LINEAR 10:1 microfocusers!
  • We will better any genuine competitor's genuine offer, if they have in stock exactly the same model w/same specifications and accessories!
The advantages of RC *Ritchey Chrétien“ Astrographs for Astrophotography :
The RC Astrograph is a real Ritchey-Chrétien reflector telescope. A high end optics known for their expencive price, now made available with an an affordable price for our indian amateur astronomers. 

Contrary to Maksutovs or Schmidt-Cassegrains which have a spherical mirrors and need image correctors, and contrary to Newtonians that need coma correctors. The RC system is a well corrected for Astro-Photography that uses only mirrors (hyperbolic primary- and secondary mirror). (no false colour) and does not require any corrector with any cameras.

RC Telescope is better, than Schmidt Cassegrain telescopes with correctors.
This is also the advantage of RC telescopes against SCT telescopes. These telescopes needs a lens corrector wich is integrated in the optical system. The RC is a true reflection system without lens corrector and with a very bright image.
Good-bye Coma :
An RC has virtually no coma (stars look like little comets around the edges of the field), which means there will be greater image quality across a wider field of view.
No Chromatic Aberration :
Because a Ritchey-Chretien does not use lenses or corrector plates, the design does not suffer from chromatic aberrations, or false color. If you've ever looked through an achromatic refractor (non-APO), you will have seen chromatic aberration.
No Spherical Aberration :
The use of hyperbolic mirrors for both the primary and secondary removes the problem of spherical aberration from this optical system, an optical effect caused when light rays do not all come to focus at the same point, resulting in an image that is not in perfect focus.
No mirror shift :
Because it has a fixed focuser, the primary mirror flop and resultant image shift issues associated with long focal length SCT telescopes with moving mirrors are avoided. There is no need for mirror locks and the additional problems these bring when it comes to focusing. There aren't any complex internal parts to move the mirrors back and forth while attempting to keep them accurately aligned so there's less to move about.
Fastest cool-down time in it's class :
Don't spend the whole night waiting for your scope to cool down. Closed tube telescopes with corrector plates such as Maksutovs and SCTs can take so long to cool down that they never reach ambient temperature during the whole night. The RC optical tube is an open design, minimising cool down time compared to SCTs with closed tubes.
Contrast and controlling stray light :
The internal knife edge baffles and matte black interior ensure high contrast and minimize the intrusion of stray light, reducing background glare on long exposure images. You will never have to to line the interior of this instrument with "flocking paper" to improve contrast - common practice with other imaging reflectors. Because there is no large corrector plate pointing at the sky, it's very rare for condensation or dew to form on the optics and it almost never occurs
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