Originally Posted by Dave Mitsky

From the Meade home page:

http://www.meade.com/rcx400/index.html

"The dream of owning the ultimate Advanced Ritchey-Chrétien telescope is finally here."

http://www.meade.com/lx200r/index.html


"Meade’s all new LX200R brings Advanced Ritchey-Chrétien optics within reach of aspiring astronomers everywhere. Nearly every observatory reflector in the world is a Ritchey-Chrétien, including NASA’s Hubble Space Telescope. Now you can own what the professionals own."

Meade's cavalier and improper use of the term Ritchey-Chrétien* has resulted in litigation.

http://www.rcopticalsystems.com/FactsofCase.html

http://www.rcopticalsystems.com/FactsofCase01.html

Is this a case of instant karma or what? (Meade sued Celestron not all that long ago.)

When all is said and done, the fact remains that R-C Cassegrains have only two optical surfaces and do not have corrector plates.

Dave Mitsky

From http://www.astronomy.com/asy/default.aspx?c=ss&id=9

Ritchey-Chrétien

This telescope design was developed jointly by American optician George Willis Ritchey (1864 – 1945) and French optical designer Henri Chrétien (1879 – 1956) in the first decade of the 20th century. These two telescope designers found that the lower the amplification factor of the secondary mirror, the flatter the field. The Ritchey-Chrétien system has a secondary mirror that magnifies 2.7x, whereas the Schmidt-Cassegrain design has a 5x secondary. The Ritchey-Chrétien design is coma-free, whereas the Schmidt-Cassegrain is not. Ritchey-Chrétien telescopes have hyperbolic primaries and secondaries that correct for coma; production-type Schmidt-Cassegrains use a spherical primary and secondary and do not correct for coma. Finally, the Ritchey-Chrétien design has two optical surfaces. All Schmidt-Cassegrains have four. Why are Schmidt-Cassegrain telescopes more popular (by far) than Ritchey-Chrétiens? One word: price. A Ritchey-Chrétien telescope is quite costly to produce and, therefore, expensive to buy.

* http://www.rfroyce.com/cassegrains.htm

* http://en.wikipedia.org/wiki/Ritchey...tien_telescope