Here's why:

* Convex Primary Mirror: Schmidt-Cassegrain telescopes use a spherical primary mirror with a convex (outwardly curved) surface.

* Flat Secondary Mirror: The secondary mirror in a Schmidt-Cassegrain design is flat and tilted at a specific angle to reflect light from the primary mirror towards the eyepiece.

* Eyepiece on Top: The eyepiece is located at the back of the telescope tube, on the same side as the primary mirror.

Let me know if you have any more questions about telescope designs!