SchmidtCassegraini

SchmidtCassegraini refers to a type of catadioptric telescope that combines elements of both the Schmidt camera and the Cassegrain telescope. This design utilizes a primary parabolic mirror and a secondary hyperbolic mirror, similar to a standard Cassegrain. However, it incorporates a Schmidt corrector plate at the front of the tube. This corrector plate is a aspheric lens that corrects for spherical aberration introduced by the primary mirror. The corrector plate also serves to block stray light.

The light path in a SchmidtCassegraini telescope begins when light enters through the corrector plate. It then reflects off the primary mirror, travels forward to the secondary mirror, which reflects it back through a central hole in the primary mirror. Finally, the light reaches the focal plane where the eyepiece or camera is located. This folded optical path allows for a relatively long focal length to be contained within a short tube, making the telescope compact and portable for its aperture.

SchmidtCassegraini telescopes are popular among amateur astronomers due to their versatility. They offer good performance for a wide range of astronomical observations, including planetary viewing, deep-sky objects like nebulae and galaxies, and even astrophotography. Their compact nature also makes them easier to transport and set up.