Best Catadioptric Where Does Focal Length Come In? My 8" Dob Is 1250, A Catadioptric 8" Is 2032.what Does This Mean?

Where does focal length come in? my 8" dob is 1250, a catadioptric 8" is 2032.what does this mean? - best catadioptric

The focal length of a telescope is the actual distance from the objective focal plane. This is a simple step in a refractor or Newtonian telescope, but it is complicated (in the Cassegrain design when Schmidt-Cassegrain or Maksutov-Cassegrain). With this design, the presence of a secondary convex mirror of focal length much longer than the physical size of the telescope. Thus an 8 "SCT has a focal length of 2032 mm in a tube that contained only about 460 mm long. This gives you the size of the image, such as Newton or refractor more than 2000 mm long.

Focal length of a telescope is determined by the size of the base image. The higher the focal length, the better the image in the focal plane. For example, a length of 1250 mm of coordination, the moon is 11 mm in diameter. With a length of 2032 mm coordination, the moon is 18 mm in diameter. With my 11 "Schmidt-Cassegrain, focal length, 2800 mm, and the moon is 24 mm in diameter.