The Cassegrain telescope - considered extinct, but again comes back to the game thanks to the Taiwanese GSO factory. We hope that it will return permanently, because this construction offers a lot of unique features and we are sure that it is very worth paying attention to it.
• cools faster than Schmidt-Cassegrain and Maksutow-Cassegrain (similar to RC Newtons)
• there is not even a residual chromatic aberration, because it is a telescope that works only on reflection, not light deflection (like RC and Newton telescopes)
• has a longer focal length than a typical RC or Newtonian one, and parametrically similar to the Maksutov telescope
• very compact design (similar to RC and Mak)
• no lens system allows the use of the Cassegrain telescope in infrared photography
• the long focal length facilitates the collimation procedure, which is a shortcoming of RC telescopes, especially if you plan to use them as an exit telescope.
In general, the Cassegrain system is - as you can read - the main mirror with the figure of a rotational and secondary paraboloids being a segment of a rotational hyperboloid. A typical drawback of these is the difficulty in making these surfaces - but this is what the GSO factory dealt with. Others include a long focal length and therefore not a large field of view - but this is often an advantage, as it eliminates flaws on the edges of the field, and at the same time gives a high scale of reproduction both in photography and in observations.
Purpose : visual observations, planetary astrophotography, compact astrophotography with high-sensitivity cameras, infrared photography.