How far can a telescope look?
It is used to indicate that a telescope parameter is not a distance, but a magnification, which is how many times the observed target is narrowed. For example, using a telescope of 10 times times to observe an object 100 meters away is equivalent to watching at 10 meters.
"Magnification" is not the first choice to buy a telescope to consider the performance indicators? Absolutely not! The magnification of the telescope is limited, due to the glass fabrication process, optical quality and other factors, the telescope effective magnification = Telescope aperture millimeter number X2, more than the magnification of this formula has no meaning, if the selection multiple too large, will lead to a serious deterioration of imaging quality.
In fact, "how far" depends entirely on the brightness of the object being observed, as long as the target is bright enough to see infinity without a telescope, such as the 6000 stars we can see with the unaided eye, which can actually be considered infinitely far away. We see more than 99.9% stars are stars, and stars are so far away from us, so that the use of the Earth's largest telescope to observe, they are still just a geometric highlight (the smaller the light, indicating that the telescope's optical imaging quality is higher; Conversely, if you see a star in a telescope with a visual surface or even a color, you can conclude that the optical system is flawed, only those celestial bodies in the solar system (such as the sun, planets, comets, etc.) or the solar system have a visual surface (such as nebulae, galaxies, Clusters, etc.) can be magnified by means of telescopes.