Telescopes with lenticular objectives - refractors - are the most universal. An optical refractor tube on a high-quality azimuthal or equatorial mount, with a properly selected set of eyepieces, is suitable for observing star clusters and for studying planetary disks. Refractors with additional accessories for ground-based observations are most often preferred by amateurs when choosing their first telescope
Reflectors collect light and focus it into the optical path by means of mirrors. As long as the large-aperture reflector is mounted on a motorized equatorial mount compensating for the Earth's rotation, the telescope will produce a high-quality and bright image suitable for photography
Catadioptric telescopes are characterized by high-quality optics and relatively small size. Such telescopes are used not only for observations of space objects, but also for ground observations. The peculiarity of catadioptric telescopes is a correctly inverted vertical image.
If you did not find a SIGETA model among the listed assortment, its production may have been discontinued. You can see the list of such products in Archive.