diff btw the Schmidt-Cassegrain n the Maksutov-Cassegrain

[huang_qingyuan]

i was wondering about the difference btw the schmidt and mak-cass..
any difference in performance and cost??
would be really thankful if anyone can clarify...

[weixing]

Hi,

i was wondering about the difference btw the schmidt and mak-cass..

The main difference is the corrector plate. The SCT corrector is a shallow, complex curve, but the MCT corrector is a deep-dish meniscus.

any difference in performance and cost??

1) MCT are usually cheaper than SCT at smaller aperture, but will be more expensive at larger aperture.
2) MCT will usually perform better than SCT in planetary due to smaller central obstruction.
3) MCT will usually have better optics than SCT from the same manufacturer because the MCT is easier to manufacture.
4) MCT will usually take longer to cool down than SCT due to thicker corrector plate.
5) MCT will be heavier than a similar aperture SCT.
6) MCT will hold collimation better (some basically don't need to do any collimation by the user if handle properly), but SCT need to collimate frequently.

Have a nice day.

[Meng Lee]

Hope in singastro, we can oraganise a C6 versus Mak 150 showdown.

[Meng Lee]

Let me add one more.
7) For the same aperture, the Mak is usually physically longer and focal length is also usually longer then SCT. F-ratio is also usually larger than SCT.

[kayheem]

SCTs from Meade and Celestron share a common threaded end to accept a variety of accessories e.g. focal reducers, photographic adaptors, flip mirrors etc.