The most important parameter of an astronomical telescope is the diameter of the main mirror and, depending on the current situation, the accuracy of the main mirror; these two indicators determine the available magnification of the telescope. Generally, good quality telescopes can provide 2 times magnification per millimeter of diameter. The maximum usable magnification of an 80 mm diameter telescope is 160 times. Of course, if you want to observe with this magnification, you must use eyepieces with appropriate focal length. For example, the main mirror focal length of this telescope is 640 mm. To obtain a magnification of 160 times, an eyepiece with a focal length of 4 mm is required.

Telescopes with excessive nominal magnification are suspected of false advertising, so it is best not to buy them.

As for what celestial objects can be seen with a telescope, this is a big topic. Here is a quote from a senior astronomy enthusiast: "A telescope is not a TV set. You can watch it by turning it on; a telescope is like a piano. The more effort you put into it, the more you will get."